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Seminars and Workshops
The following seminars and workshops are planned:

Workshops HPCI Field 5 - iTHES Joint International Workshop "Study of Neutron Stars and Core-Collapse Supernovae" Dec. 16, 2014 - Dec. 20, 2014 Place: Dec. 16 (The.): 3rd floor of Frontier Research Laboratory (Area F-5, building No.15 in the map) Dec. 17 (Wed.) - 20 (Sat.) : Main Research Building (Area F-6, building No.1 in the map) http://www.riken.jp/~/media/riken/access/wako-map/map2_en_p_140601.pdf Program: ------------------------------------------ International Workshop on “Study of Neutron Stars and Core-Collapse Supernovae”, organized by HPCI Strategic Program Field 5 and RIKEN iTHES Reseach Group. Date: Dec. 16, 2014 - Dec. 20, 2014 Place: RIKEN, Wako Campus Dec. 16 (Tue.) (Frontier Research Laboratory, 3F, meeting room) 10:00 - 10:10 Opening address: E. Hiyama (RIKEN) 10:10 - 10:50 G. J. Mathews (Notre Dame) “Neutrinos and nucleosynthesis in core-collapse supernovae” 10:50 - 11:20 Wongwathanarat Annop (RIKEN) “3D core-collapse simulations: from shock revival to shock break-out” 11:20 - 11:50 H. Sotani (NAOJ) “Massive hybrid star with strong magnetic field” 13:30 - 14:00 T. Saito (GSI) “Three-body hypernuclei studied by heavy ion collisions” 14:00 - 14:30 A. Feliciello (Torino) “Observation of neutron-rich Λ-hypernuclei by the FINUDA experiment” 14:30 - 15:00 S. N. Nakamura (Tohoku) “Electro-Production of Lambda Hypernuclei” 15:30 - 16:00 E. Hiyama (RIKEN) “ΛN-ΣN coupling effect in neutron-rich nuclei” 16:00 - 16:30 A. Tamii (RCNP) “Constraints on S0 and L from measurements of electric dipole response on heavy nuclei” 16:30 - 17:00 H. Togashi (RIKEN) “Equation of state for hyperonic nuclear matter with the cluster variational method” Dec. 17 (Wed.) (Main Research Building, 4F, 435?437) 10:00 - 10:40 Myung-Ki Cheoun (Soongsil) “Pairing correlations in the symmetry energy and the equation of state” 10:40 - 11:20 K. Hagino (Tohoku) “Dineutron correlations in neutron-rich nuclei” 11:20 - 12:00 T. Miyatsu (Soongsil)“Equation of state for neutron stars with hyperons and quarks using relativistic Hartree-Fock approximation” Dec. 18 (Thu.) (Main Research Building, 5F, 535?537) 10:00 - 10:40 T. Takiwaki (RIKEN) “Impact of electron capture rate and equation of state on supernovae explosions” 10:40 - 11:20 S. Furusawa (NAOJ) “Equations of state at sub-nuclear densities and weak interactions in Supernovae” 11:20 - 12:00 T. Maruyama (Nihon) “Pion Synchroton Radiation from Proton in Neutron Star with Strong Magnetic Field” Dec. 19 (Fri.) (Main Research Building, 4F, 435?437) 10:00 - 10:40 A. B. Balantekin (Wisconsin-Madison) “Neutrinos and core-collapse supernovae” 10:40 - 11:20 Y. Pehlivan (Mimar Sinan Fine Arts) “Is a model independent analysis of collective neutrino oscillations possible?” 11:20 - 12:00 T. Kajino (NAOJ) “Supernova neutrinos, r-process and EoS” Dec. 20 (Sat.) (Main Research Building, 4F, 435?437) Free Discussion Day --------------------------------------------------------------- Organizers, E. Hiyama(RIKEN), T. Kajino(NAOJ), Y. Funaki(RIKEN), T. Hatsuda(RIKEN), H. Togashi(RIKEN)
Seminars Luca Baiotti Osaka Univ. General Relativistic Simulations of Binary Neutron-Star Mergers 12th Dec. 2014, 14:30-15:30 Room 435-437 in the Main Research Building
Seminars Haoning HE University of California, Los Angeles, Physics & Astronomy The possible origins of Sub-PeV to PeV neutrinos observed by the IceCube and of Ultra-High-Energy Cosmic Rays at the Telescope Array Hotspot Dec 4 (Thu) 15:00 - Main Research bldg. 433
Seminars Alexander KUSENKO University of California, Los Angeles, Physics & Astronomy Cosmic rays and gamma rays from blazars Dec 4 (Thu) 14:00 - Main Research bldg. 433
素核宇宙融合レクチャー 長瀧重博 理化学研究所長瀧天体ビッグバン研究室 Why Astrophysical Big Bang? 11/27 13:00-17:30, 11/28 9:00-15:00 研究本館435-437号室
Seminars Prof. Gordon Baym Univ. of Illinois at Urbana Champaign The Superfluid Mass Density and the Landau Criterion for Superfluidity Nov.20 (Thur.) 3pm-5pm Main research building, 4th floor, room 433 A finite superfluid mass density is the defining characteristic of superfluids and superconductors. In this talk I will discuss the phenomenology and the microscopic theory of the superfluid mass density. I will then address why the commonly used Landau criterion for superfluidity is neither necessary nor sufficient to have superfluidity. Finally I will discuss experiments, past and future, on the superfluid mass density in ultracold bosonic and fermionic atomic systems.
Seminars QCD Club supported by iTHES 青木 保道 氏 (名大KMI) 11月13日(木) 15時-17時 研究本館4階会議室433 title: コンフォーマル的な格子QCDの話題
Seminars Keitaro Takahashi Graduate School for Science and Technology, Kumamoto University New Era of Astronomy with Square Kilometre Array 14:00-15:00, 12th Nov. 2014 Room 224-226 in the Main Research Building
Seminars Professor Jonathan H. Manton University of Melbourne Optimisation on Manifolds, and Optimisation Geometry 13:30-, November 11, 2014 S406, Bioscience Building 4F, RIKEN http://www.riken.jp/en/access/wako-map/#campus_map Abstract: The past decade has seen a surge of interest in optimization on manifolds, driven by the fact that some real-world problems are best formulated on a manifold such as a Grassmann or Stiefel manifold, or even on a more structured space such as a Lie group. A basic question to ask, and one with a long history, is how the Newton method can be extended to a manifold. A partial answer, in the form of a general framework, has been given recently ( http://arxiv.org/abs/1207.5087 ). Interestingly, studying the more general context of optimization on manifolds leads to new insight into the Euclidean case. Having reviewed this, the talk then focuses on what we call real-time optimization. Here, geometry plays a prominent role because the class of cost functions as a whole can be treated as a fiber bundle. This research is in its infancy but it is speculated there will be close connections between geometry and the complexity of (real-time) optimization; a link with Smale's notion of topological complexity can already be made. Finally, the question is asked whether the current dichotomy in optimization, that convex problems are easy and all other problems are hard, is an artefact of focusing on the Euclidean case and neglecting other rich geometric structures.
iTHES-IPMU-Osaka TSRP Symposium "Frontiers of Theoretical Science ? MATTER, LIFE and COSMOS - " Nov. 6 (Thu.) 2014 Kavli IPMU, Univ. Tokyo (http://www.ipmu.jp/ ) Invited speakers: H. Ooguri (IPMU/Caltech), H. Murayama (IPMU/Berkeley), E. Komatsu (Max-Planck-Institut fur Astrophysik), F. Nori (iTHES/CEMS), Y. Sugita (iTHES/AICS), K. Fujimoto (Osaka) Program & Registration: http://indico.ipmu.jp/indico/conferenceDisplay.py?ovw=True&confId=44
Seminars Prof. Jooyoung Lee Center for In Silico Protein Science, KIAS, Korea Protein Structure Modelling by Global Optimization using Sparse and Ambiguous NOE restraints 10:30 - 11:30 AM, November 5th (Wednesday) Main Research Building (研究本館)435/437
Seminars Dr. Giandomenico Palumbo, School of Physics and Astronomy, University of Leeds, UK Induced topological order at the boundary of 3D topological superconductors Tuesday, November 4, 14:00- Main Research Building Seminar room 435-437 (located in the Fourth Floor) We present tight-binding models of 3D topological superconductors in class DIII that support a variety of winding numbers. We show that gapless Majorana surface states emerge at their boundary in agreement with the bulk-boundary correspondence. At the presence of a Zeeman eld the surface states become gapped and the boundary behaves as a 2D superconductor in class D. Importantly, the 2D and 3D winding numbers are in agreement signifying that the topological order of the boundary is induced by the order of the 3D bulk. Hence, the boundary of a 3D topological superconductor in class DIII can be used for the robust realisation of localised Majorana zero modes. Reference: Peter Finch, James de Lisle, Giandomenico Palumbo, Jiannis K. Pachos, arXiv:1408.1038.
Seminars Nobuya Nishimura Keele University, EPSAM(Research Institute for the Environment, Physical Sciences and Applied Mathematics), UK Nuclear physics uncertainty studies of nucleosynthesis beyond iron based on a general framework of Monte-Carlo 14:00-15:00, 31st Oct.2014 Meeting Room (S) 2, 2F Welfare and Conference Building
Seminars Dr. Akiko Ueda, Division of Applied Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, Japan Detecting Majorana fermions of class BDI topological superconductors by transport measurements Thursday, October 30, 14:00- Main Research Building Seminar room 315 (located in the Third Floor) Observation of Majorana fermions (MFs) has been one of recent hot topics in condensed matter physics. Much effort has been devoted to the detection of MFs. Just this month, Yazdani group has observed the strong evidence for Majorana fermions using an atomically thin chain and a scanning-tunneling microscope[1]. The result opens the new stage of research; e.g. exploring new materials for stable MFs and controlling the MFs which can be useful for the quantum computing. The topological superconductors(TSs) are classified to some classes. The materials that experimentalists usually are hunting MFs belong to the class D TSs, in which only one MF emerges at an edge or a vortex of the system. We have theoretically examined the different type of the TS called the class BDI. In the class BDI TS, two MFs exist at an edge or a vortex. We have considered a system with an Aharonov-Bohm ring with an embeded quantum dot coupled to the class BDI topological superconducting wire to detect the interference due to MFs[2]. We have revealed the anomalous features due to the existence of the MFs in the Aharonov-Bohm oscillations. [1]Stevan Nadj-Perge et al., Science (Express) (2014). [2]Akiko Ueda and Takehito Yokoyama, Physical Review B, Vol. 90, 081405(R) (2014).
Seminars Dr. David Zueco, Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad Zaragoza, Spain Quantum Nonlinear Optics with few photons, strong and ultrastrong light-matter coupling cases. Tuesday, October 28, 13:15- Main Research Building Seminar room 435-437 (located in the Fourth Floor) In this talk I will present our recent results on the N-photon scattering propagating in one dimensional waveguides coupled to M qubits. Qubits and waveguide can be strongly or ultrastrongly coupled. Photon-photon correlations, transmission, inelastic channels and non Markovian evolution for the qubits will be discussed. The linear - nonlinear behavior as a function of the ratio N/M will be deeply discussed. Both the Rotating Wave approximation (strong coupling) and beyond RWA (ultrastrong) will be analyzed and compared. Work in progress considering dissipative effects and photon generation will be announced.
Seminars Dr. Konstantin Bliokh, Quantum Condensed Matter Research Group, CEMS, RIKEN Extraordinary momentum and spin in evanescent waves Friday, October 24, 14:00- Main Research Building Seminar room 315 (located in the Third Floor) Momentum and spin represent fundamental dynamical properties of quantum particles. For photons,momentum is associated with the wave vector and is independent of polarization. In turn, spin is associated with a circular polarization and is also collinear with the wave vector. We show that situation becomes strikingly different for evanescent optical waves. First, evanescent waves possess momentum component, which depends on circular polarization and is orthogonal to the wave vector. Second, there is a spin angular momentum, which is largely independent of the polarization, and is also orthogonal to the wave vector. Although these extraordinary properties seem to be in contradiction with what we know about photons, we show that they reveal a fundamental quantum spin current hidden in propagating fields. Numerical calculations of the Mie scattering demonstrate that the transverse momentum and spin push and twist an absorbing probe particle in an evanescent field, so that they can be detected straightforwardly.
Seminars Kenichi Nishikawa University of Alabama in Huntsville Radiation from accelerated particles in relativistic jets with shocks and shear-flow 14:30-15:30, 17th Oct.2014 Room 435-437 in the Main Research Building
Lecture Series for Industry-Academia Cooperation in Mathematical Science iTHES Special Lecture on Financial Engineering (in Japanese) 14:00-, Sept. 30 (Tue.) 2014 the large meeting room on the 2nd floor of the Main Cafeteria Lecturers: J. Hashiba and Y. Takano (MIZUHO-DL Financial Technology) 産学連携数理レクチャーシリーズ みずほ第一ファイナンシャルテクノロジー株式会社 福島 良治(取締役) 高野 康 (金融工学第二部 副部長) 羽柴 次郎(金融工学第二部 副部長) http://www.mizuhobank.co.jp/fintec/index.html 9月30日(火)14:00-18:00 (レクチャー全体で3時間程度、途中休憩を1時間程度含む)。18:15-20:15にバンケットを予定。 統合支援施設大会議室 冒頭の紹介は5-10分程度。その後以下3テーマを3時間弱でレクチャー。 冒頭:みずほ第一ファイナンシャルテクノロジー株式会社の紹介 i.金融実務と金融工学の全体感 ii.金融工学における数理モデルの具体例 iii.技術的な課題 i.金融実務と金融工学の全体感 銀行、保険会社、一般事業会社等の業務内容を俯瞰した上で、その中で特に金融工学を必要とするような金融実務と、その金融実務で使われる金融工学の概要を紹介 ■例 ・資産運用 ・リスク管理 ・デリバティブ等の金融商品開発 ii.金融工学における数理モデルの具体例 金融工学で用いられる数理モデルの具体例を紹介 ■例 ・リスク管理:Mertonの企業価値モデル ・デリバティブのプライシング:Black-Scholesモデル iii.技術的な課題 金融工学の実務応用における技術的な課題 ■例 ・モンテカルロ・シミュレーションの高速化
Seminars 8th QCD Club supported by iTHES "Quantum Entanglement and Spacetime Geometry" Prof. T. Takayanagi (YITP, Kyoto Univ.) Sep.29 (Mon) 15:00-17:00 Main Research Building room 433 (4th floor) Abstract: The discovery of AdS/CFT correspondence in string theory has largely changed our understandings of spacetimes in gravity. Especially, if we reconsider the AdS/CFT from quantum information theoretic viewpoints, we find a novel emergence of spacetime from tiny bits of quantum entamglement. This enables us to relate gravitational spacetimes to tensor networks, which in the context of AdS/CFT, correspond to so called entanglement renormalization (MERA). In this talk, I would like to overview these recent developments on the holographic spacetimes from the viewpoint of quantum entanglement. Organizers: T. Kanazawa (RIKEN), Y. Hidaka (RIKEN) K. Fukushima (Univ. Tokyo), A. Yamamoto (Univ. Tokyo) http://tkynt2.phys.s.u-tokyo.ac.jp/hadron/qcdclub.html
Seminars 放射線の生物影響の統一的考察: 動物から植物まで 坂東昌子 (NPO法人あいんしゅたいん理事長, 第62期日本物理学会会長) http://jein.jp/npo-introduction/officer-greeting.html 2014年9月10日(水)午後3時ー 生物科学研究棟3階大セミナー室(S311) 要旨: 低線量放射線の生物への影響の評価については、さまざまな議論がある。 こういうとき、物理屋は、「統一的に理解できるか」「定量的な議論ができるか」と考える。3.11以後、さまざまな議論を聞いているうちに、物理屋の出番だと思った。そして、3年かけて、やっと模型を構築し、現象論を始めることができた。 大切なことは「生きている生物は外部の刺激によるリスクに対して修復力がある。これをきちんと取り入れるためには、インプットアウトプットの 攻防を時間的に追う必要がある。ということは、現在生体リスクを総線量を基本 にした評価は肝心の点を考慮していない」ということである。もっと大切なのは、線量率依存性である。線量率を取り入れた模型を、我々はWhack A Mole(WAM) と名付けた。WAMを用いて、マウス・ハエ・トウモロコシ・キク・ムラサキツユクサを分析し、統一的なピクチャーが得られることを示す。そして今後の展望を議論したい。 共同研究者: 坂東昌子(ばんどう・まさこ) NPO法人あいんしゅたいん、 京都大学基礎物理学研究所、大阪大学核物理研究センター (専門分野/関心分野) 素粒子論、非線形物理学、交通流、低線量放射線の生体影響 真鍋勇一郎(まなべ・ゆういちろう) 大阪大学 大学院工学研究科 環境・エネルギー工学専攻  量子エネルギー工学講座 (専門分野/関心分野) 原子核物理、低線量放射線の生体影響 中村一成(なかむら・いっせい) 中国科学院長春応用化学研究所 (専門分野/関心分野)ソフトマター物理、計算化学、生物物理 中島裕夫(なかじま・ひろお) 大阪大学大学院 医学系研究科 医学専攻 ゲノム生物学講座  放射線基礎医学教室 (専門分野/関心分野) 放射線基礎医学、発生遺伝学、ナノ医学 角山雄一(つのやま・ゆういち) 京都大学 環境安全保健機構 放射性同位元素総合センター (専門分野/関心分野)分子生物学、放射線安全管理
Workshops Osaka-iTHES joint workshop on "Turbulence and Chaos in AdS/CFT" Sep. 8 (Mon), 2014 Room H701, 7th floor, Phys. Dep. Osaka Univ. * program 10:20-11:40 Turbulence in AdS (including review) Akihiro Ishibashi (Kinki U.) 13:00-13:40 Turbulence on the brane in holographic QCD Shunichiro Kinoshita (Osaka city U.) 13:40-14:20 Nonequilibrium quantum dynamics as a quantum walk in energy space Takashi Oka (Tokyo U.) 15:00-15:40 Review on Integrable Classical String Solutions in AdS/CFT Hen-Yu Chen (National Taiwan U.) 15:40-16:20 Chaos and Non-Integrability in AdS/CFT Kentaroh Yoshida (Kyoto U.) 16:20-17:00 Chaos in Lifshitz spacetimes (TBA) Bum-Hoon Lee (Sogang U / CQuest) 17:00-17:05 Concluding words by K.Hashimoto*program(if any): *Access to the venue: http://www-het.phys.sci.osaka-u.ac.jp/access-e.html
Workshops 理研シンポジウム・iTHES研究会 「熱場の量子論とその応用」 2014年9月3日(水)〜9月5日(金) 理化学研究所 大河内記念ホール http://www.riise.hiroshima-u.ac.jp/TQFT/
Workshops Supernovae and Gamma-Ray Bursts 2014 Aug.25(Mon)-27(Wed), 2014 Ookouchi Hall About 15 people have been invited to give a talk at the workshop, and about 10 people of iTHES/RIKEN members (all are astrophysicists) will give a keynote talk. We may have a few contributed talks. Everyone is welcome to join us if you are interested in the workshop. The talks are given in Japanese or English, and the slides are written in English.
Seminars Dr. Marcin Wiesniak, Institute of theoretical Physics an Astrophysics, University of Gdansk, Poland Experimental Complementarity Between Kinds of Multipartite Entanglement Wednesday, August 20, 14:00- Main Research Building Seminar room 435-437 (located in the Fourth Floor) Entanglement is a fascinating feature of quantum theory, which allows systems to be described only in reference to each other. In its radical form it allows falsification of local realism through violation of Bell inequalities (BIs). Even though there is a large variety of BIs known, we still miss the full picture. The presented method starts with describing systematic method of deriving BIs for collections of qubits, which utilize subcorrelations (correlations between subsets of all investigated qubits). They allow to observe five-partite entanglement even in states, which show no correlations between all five qubits. Next, we notice that these inequalities are violated if a certain condition is satisfied, from which we build a quadratic entanglement criterion. Namely, with use of bound of the squared sums of mean values of the operators used in the entanglement indicator in cases when they commute or anticommute, we recognize a linear structure describing the relations between the correlation tensor. Next, we construct graphs of commutativity relations of the operators. From the graphs we can find the maximal values of the indicator for various classes of separability. Two such criteria were chosen for an experiment-one for cluster states, the other for GHZ correlations. They both could be tested with only two measurement series. As it turns out, these two criteria combined reveal complementarity between two kinds of multipartite quantum correlations: one indicator can be maximized only at the expense on the other, yet for all invetigated states, the combine indicator always shows genuine four-partite correlations.
DAC テラヘルツ波分光ミニ研究会 日時:2014 年 8 月 1 日[金] 13:30〜17:30 場所:理化学研究所仙台地区 共催:理研 理論科学連携研究推進グループ(iTHES) 協賛:みやぎ産業科学振興基金 内容:本研究会では,理研と岐阜大学が共同研究として取り組んでいるダイヤモ ンド・アンビル・セル(DAC)を用いた高圧環境下における氷やガスハイドレー トのテラヘルツ波分光に関して,各チームにおける最近の研究成果について議論 するとともにその将来展開について深く議論する場を提供する. ~プログラム~ 13:30 「開会の挨拶」 南出 泰亜(理研) 13:40 「テラヘルツ帯広帯域分光ストークス偏光計測システムの開発と応用」 野竹 孝志(理研) 14:10 「非線形光学波長変換による 1~3THz 帯高感度計測システムの開発」 瀧 田 佑馬(理研) 14:40 「完全重水素化メタンハイドレートの高圧ラマン散乱」 佐々木 重雄(岐阜大) 15:10 「メタンハイドレート高圧相の構造と分光:理論予測」 飯高 敏晃(理研) 15:40 コーヒーブレイク 16:00 「今後の共同研究について」 16:40 実験室見学 18:30 懇親会(仙台市街にて開催予定,会費別途) 【敬称略,講演時間に質疑応答を含む】 連絡先:理化学研究所 テラヘルツ光源研究チーム 瀧田 佑馬
iTHES-HPCI Joint Summer School "From Quarks to Supernova explosion - Challenges in Fundamental Physics -" July 22 (Tues) - 26 (Sat), 2014 Yukawa Institute for Theorerical Physics (YITP), Kyoto http://www.jicfus.jp/field5/jp/140722-26summerschool/
Seminar Prof. Gyuri Wolf (KFKI, Hungary) Dilepton production in pion-nucleon and pion-nucleus reactions July 10, 3pm- RIKEN Main Research Building 4F, 433 We calculate electron-positron pair production in pion-nucleon and pion-nucleus collisions. We derive the elementary cross sections in an effective field theory approach. We use these cross sections in a transport model to study π-nucleus reactions. We investigate especially what is the effect of the in-medium modification of vector mesons on the dilepton invariant mass spectra using the propagation of spectral functions of vector mesons. Furthermore, we study the effect of the interference term (which is destructive in pi+ n and constructive in pi-p collisions) of the ρ and ω mesons on the dilepton spectra in pi+ A and pi- A collisions. These results are meant to give predictions for the planned experiments at the HADES spectrometer in GSI, Darmstadt. These reactions may be studied in JPARC, too.
Workshops iTHES-Kavli IPMU-RESCEU Joint Meeting 7-8 July, 2014 Nishina Hall, Wako Campus This joint meeting is one of our activities based on the research partnership MOU between iTHES and Kavli IPMU (http://www.ipmu.jp/node/1781). Kavli IPMU: http://www.ipmu.jp/ RESCEU, the Univ. of Tokyo: http://www.resceu.s.u-tokyo.ac.jp/top_en.php Program 7th July 9:50-10:00 Opening Remarks 10:00-10:40 Robert Quimby (IPMU) : Unusually Bright Supernovae 10:40-11:20 Maria Dainotti (RIKEN): GRB Cosmology 11:20-11:50 Coffee Break 11:50-12:30 Maxim Barkov (RIKEN): GRB Engine and Relativistic Flow 12:30-14:00 Lunch 14:00-14:40 Jin Matsumoto (RIKEN): Relativistic MHD/HD Flow for GRB Jets 14:40-15:20 Toshikazu Shigeyama (RESCEU): r-process enrichment by Neutron star mergers 15:20-16:00 Shinya Wanajo (RIKEN): r-process nucleosynthesis 16:00-16:30 Coffee Break 16:30-17:10 Yu Komiya (RESCEU): Chemical evolution of r-process elements in hierarchical galaxy formation models 17:10-17:50 Miho Ishigaki (IPMU): Chemical abundances in extremely metal-poor stars in the Milky Way halo and in dwarf satellite galaxies 18:15-20:15 Banquet (at Hirosawa Club in Campus) 8th July 9:00-9:40 Tomoya Takiwaki (NAOJ -> RIKEN): Explosion Mechanism of CC-SNe 9:40-10:20 Hiroki Sato (U. of Tokyo) : SPH simulation of double white dwarf merger 10:20-11:00 Shiu-Hang Lee (JAXA/RIKEN): Supernova Remnants 11:00-11:30 Coffee Break 11:30-12:10 Alexey Tolstov (IPMU/RIKEN): Simulations of supernova light curves and spectra using multigroup radiation hydrodynamics 12:00-12:50 Yukari Ohtani (RESCEU): Theoretical expectation of supernova shock breakout in the relativistic limit 12:50-14:00 Lunch 14:00-14:40 Yasunobu Uchiyama (Rikkyo): Review of Gamma-Ray Observations for Galactic Sources 14:40-15:20 Nozomu Tominaga(Konan/IPMU): Development of a multidimensional relativistic radiative transfer code 15:20-15:40 Coffee Break 15:40-16:20 Hirotaka Ito (RIKEN): Photospheric Emission in GRBs 16:20-17:00 Yuto Teraki (RIKEN): Wiggler Radiation in Langmuir turbulence; a possible emission mechanism of GRB 17:00-17:10 Closing Remarks Each speaker has 30min for presentation and 10min for Q&A. Presentations are given in English. (世話人) 長瀧重博(チェア)、Alexey Tolstov、茂山俊和、松本仁、伊藤裕貴、寺木悠人、 Maria Dainotti, Maxim Barkov, Shiu-Hang Lee, 和南城伸也、滝脇知也、 水田晃、野本憲一、初田哲男 (参加申込・一般講演申込) 当日参加も受け付けておりますが、会議運営上、参加ご希望の方は以下のフォームにご記入頂き、長瀧までご返信頂ければ幸いです。特に懇親会参加ご希望の方におかれましては、ご希望受付の締切を6月15日とさせて頂きたく思います。 みなさまにお目にかかれることを世話人一同、心待ちにお待ちしております。 どうぞよろしくお願いいたします。 以下のフォームを、長瀧 shigehiro.nagataki@riken.jp までお送りください。 ----------------------------------------------------------------- RIKEN-IPMU-RESCEU Joint Meeting ご参加申込みフォーム ご氏名: 所属: 身分: 懇親会参加ご希望: あり or なし(参加ご希望の申込締切は6月15日) メモ(何かご要望等、ありましたら): -----------------------------------------------------------------
Seminar Prof. W. Weise (ECT*) "Topics in Low-Energy QCD with Strange Quarks" 16:00-17:30, June 30 (Mon), 2014 RIKEN Main Research Building 4F, 433
Seminars Sergei Blinnikov, ITEP/IPMU What is the Zeldovich number, and what was his life-time favorite problem 20th June, 14:30-15:30 Room 435-437, Main Research Build. http://nagataki-lab.riken.jp/Seminar.html
Seminars Shigeo Kimura, Osaka Univ. Effects of High Energy Particles on Accrtion Flows 20th June, 15:30-16:30 Room 435-437, Main Research Build. http://nagataki-lab.riken.jp/Seminar.html
Seminars Dmitry Khangulyan, ISAS Gamma-Ray Emitting Binary Systems 2 June 2014, 17:00 2F Large mtg.rm, Main Cafeteria which is in the building No. 39 of this map http://www.riken.jp/access/wako-map/ Pulsars and pulsar wind nebulae (PWN) represent the most numerous class of galactic gamma-ray emitting sources. However, only one pulsar (with a few candidates) located in binary systems is confirmed as gamma-ray emitters. Typical binary pulsars accrete material from companion stars, and the gravitation energy is released through bright X-ray emission. However, the accretion process significantly affects the pulsar magnetosphere, and in particular this ceases the pulsar wind, which is essential for formation of PWN. Therefore, to be a gamma-ray emitter binary system should contain a pulsar powerful enough to prevent the accretion. In this case a compactified nebula can be formed in binary systems. However, this type of sources features several important differences as compared to their isolated siblings. Several factors, e.g., environmental impact and hydrodynamic interaction regime, have crucial influence on the processes occurring in gamma-ray binary systems. I will review in detail the physical scenario for binary pulsars and will discuss the implication of different observational data, obtained with both ground based and space gamma-ray detectors.
Workshops iTHES Mini-workshop on "Strong-Field Physics" 11:00am-, May 29 (Thu.) 2014 Room 433, 4th-floor, Main Research Building, RIKEN program: -11:00-11:45 K. Hattori (RIKEN) Photon propagations in strong magnetic fields -11:45-12:30 T. Tomaru (KEK) Vacuum Birefringence and Axion measurement by laser interferometer -13:45-14:30 T. Tamagawa (RIKEN) TBA -14:30-15:15 M. Barkov (RIKEN) Close binary progenitors of gamma-ray bursts and hypernovae -15:35-16:20 T. Moritaka and H. Takabe (ILE, Osaka University) Gamma Ray Emission and Induced Vacuum Breakdown with High-Intensity Pulse Laser -16:20-17:05 T. Ebisuzaki (RIKEN) Astrophysical ZeV acceleration along the jets of an accreting blackhole -17:05-18:00 Free discussions
Workshops International workshop on "Intersection of cold-atomic and nuclear physics" May 12-13, 2014 APCTP, Pohang, Korea http://lambda.phys.tohoku.ac.jp/nstar/symposium/2017.html The aim of this workshop is to share recent researches in Asia on cold atoms, nuclei, and nuclear matter, which we believe are fields with much overlapping physics among them. We hope this workshop can stimulate the exchange of ideas and encourage international and interdisciplinary collaboration to establish the equation of state (EOS) of nuclear matter. For this purpose, we plan to keep an informal atmosphere with limited number of participants, to provide adequate time and opportunity for discussion and mutual interaction.
Seminars Prof. Stephen C. Rand, MURI Center for Dynamic Magneto-Optics, Physics, Appl. Physics & EECS, Optics & Photonics Laboratory, University of Michigan, USA Optical Magnetism for Solar Energy? Monday, April 28, 13:30-15:00 Main Research Building Seminar room 435-437 (located in the Fourth Floor) In this talk the recent discovery of transverse optical magnetism will be described in detail and its potential application to the parametric conversion of light energy directly into electricity will be explored. The fact that dynamic magneto-optic phenomena may be relevant to efficient solar power generation and other radically new photonic technologies some fifty years after the discovery of nonlinear optics will illustrate how the traditional scientific method can still provide astonishing developments in mature areas of science and practical solutions for the modern world. The magnitude of second-order optical charge separation and induced transverse optical magnetization will be contrasted with that of traditional magneto-optic effects.
Seminars Shigeru Shinomoto (Kyoto University) Reading neuronal spike trains 13:30〜15:00, April 24 (Thu.), 2014 Main Research Building (研究本館) 4F, 433 Short-lasting events such as neuronal electrical discharges called spikes are often treated as point events in the time axis. Propercharacterization of a temporal sequence of point events may provide the information about underlying mechanisms and the predictive information for coming events to a possible extent. The regularity can be defined by the distribution of intervals between consecutive events. Given an apparently irregular sequence of point events, we may interpret it as being derived either regularly from the rate modulated in time, or irregularly from the constant rate. We established a state-space method for estimating the instantaneous rate and regularity to determine which interpretation is more plausible given a time series of events [1,2]. We found that the degree of regularity is different between spike trains of neurons in different functional cortical areas [3]. The analysis was also applied to temporal sequences of earthquakes, correlating the occurrence irregularity to tectonic plate motion [4]. [1] Shimokawa and Shinomoto (2009) Neural Comput. 21:1931-1951. [2] Koyama, Omi, Kass, and Shinomoto (2013) Neural Comput. 25:854-876. [3] Shinomoto et al., (2009) PLoS Comput. Biol. 5:e1000433. [4] Zhao, Omi, Matsuno and Shinomoto (2010) New J. Physics 12:063010.
Seminars 篠本滋 Shigeru Shinomoto (Kyoto University) 【1】脳の働きについて 【2】理論モデリングとデータ解析 2014年4月23日(水)13:30〜15:00, 15:30〜17:00 研究本館 4階 435-437 【1】脳科学の歴史を紹介し,脳の機能と構造についての知識をまとめる.  * 参考文献「脳科学のテーブル」外山敬介・甘利俊一・篠本滋(京都大学学術出版会, 2008) 【2】神経系の働きを数理的にモデリングする研究の歴史を紹介し,さらには現代の実験によって得られたビッグデータをもとにモデル選択を行う統計手法についての紹介を行う.
Workshops iTHES mini workshop on Cloaking, Photonic Lattice & Metamaterial 13:30~17:30, April 14(Mon.), 2014 Main Research Building 4F, Seminar Room 435-437 13:30-14:20 Masato Taki Asymmetric cloaking, effective Lorentz force and photonic resonator lattice 14:30-15:20 Tomohiro Amemiya TBA 15:20-15:40 coffee break 15:40-16:30 Takuo Tanaka Towards Three-dimensional Optical Metamaterials 16:40-17:30 Tomoki Ozawa Berry curvature and quantum Hall effects in photonic lattices https://sites.google.com/site/ithescloaking2014/
Seminars Dr. Zhou Li, Department of Physics, McMaster University, Canada Modified Dirac fermions in valleytronic materials and topological insulators Friday, March 28, 10:30-11:30 Main Research Building Seminar room 435-437 (located in the Fourth Floor) In this talk I will investigate various spin-orbit interactions. As is well known, Rashba spin-orbit interaction is the key for spintronics. In Graphene and topological insulators, the Hamiltonian is similar but with the strength of spin orbit interaction to be at least 100 times bigger, making the system cross over from Schrodinger fermions to Dirac fermions. Other kind of spin-orbit interaction exists in Graphene and Graphene-like materials, for example, the Haldane spin orbit interaction, which plays an important role in spin-valley coupled systems typical for valleytronics. Other Hamiltonian (e.g. warping) and the transport properties (optical and magneto-optical, for example) will be discussed. Finally the impact of electron-phonon interaction on these systems will be addressed. Reference: [1] Zhou Li and J. P. Carbotte, Phys. Rev. B 87, 155416 (2013). [2] Zhou Li and J. P. Carbotte, Phys. Rev. B 88, 045414 (2013). [3] Zhou Li and J. P. Carbotte, Phys. Rev. B 88, 045417 (2013). [4] Zhou Li and J. P. Carbotte, Phys. Rev. B 88, 195133 (2013). [5] Zhou Li, F. Marsiglio and J. P. Carbotte, Scientific Reports 3, 02828 (2013). [6] Zhou Li and J. P. Carbotte, Phys. Rev. B 86, 205425 (2012).
Seminars Prof. Matthias Troyer, Institute for Theoretical Physics, ETH Zurich, Switzerland Quantum Annealing and the D-Wave Devices Wednesday, March 19, 2014, 16 : 00 〜 17 : 00 Main Research Building Seminar room 435-437 (located in the Fourth Floor)
Seminars Prof. Matthias Troyer, Institute for Theoretical Physics, ETH Zurich, Switzerland Validation of quantum devices Wednesday, March 19, 2014, 14 : 00 〜 15 : 00 Main Research Building Seminar room 435-437 (located in the Fourth Floor) About a century after the development of quantum mechanics we have now reached an exciting time where non-trivial devices that make use of quantum effects can be built. While a universal quantum computer of non-trivial size is still out of reach there are a number commercial and experimental devices: quantum random number generators, quantum encryption systems, and analog quantum simulators. In this colloquium I will present some of these devices and validation tests we performed on them. Quantum random number generators use the inherent randomness in quantum measurements to produce true random numbers, unlike classical pseudorandom number generators which are inherently deterministic. Optical lattice emulators use ultracold atomic gases in optical lattices to mimic typical models of condensed matter physics. Finally, I will discuss the devices built by Canadian company D-Wave systems, which are special purpose quantum simulators for solving hard classical optimization problems.
Seminars Dr. Hui Jing, Department of Physics, Henan Normal University, China Ultralow-threshold phonon laser in PT-symmetric resonators Friday, March 14, 2014, 14 : 00 〜 Main Research Building Seminar room 535-537 (located in the Fifth Floor) The parity-time-symmetric structure was experimentally accessible very recently in coupled optical resonators (COR); also for normal or non-PT-symmetric COR, a phonon laser had been created in Caltech. Here we study cavity optomechanics of this system with now a tunable gain-loss ratio. We find that nonlinear behaviors emerge for cavity photons around the balanced point, resulting giant enhancement of optical pressure and then enabling an ultralow-threshold phonon laser. I will try to give a summary of this project and also other related works on optomechanics, aiming to get your comments/suggestions/interests on it.
Workshops International Molecule-type Workshop on New correlations in exotic nuclei and advances of theoretical models March 10 - 23, 2014 Yukawa Institute, Kyoto University URL: http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=51665
Seminars Igor Shovkovy (Arizona State University) Magnetic Dance in a Quantum World 15:00-, March 5, 2014 (planned) room 433 (planned) Studies of relativistic matter in strong magnetic fields attracted a lot of attention in recent years. Some of these studies are motivated by the relativistic physics in compact stars, the Early Universe, and relativistic heavy ion collisions. Many aspects of the same underlying physics are also relevant for a growing class of novel quasi-relativistic condensed matter materials. The examples include graphene and Dirac/Weyl semimetals. Such materials attracted a lot of attention in recent years because of their unusual electronic properties and a great potential for wide-ranging applications. I will review some conceptual ideas about the underlying physics of relativistic matter in strong magnetic fields from a standpoint of a high-energy physicist with cross-disciplinary interests.
Workshops Interdisciplinary workshop "Quarks, nuclei, and neutron stars" March 5, 2014, 10:00 am- (time is tentative) Faculty of Science, Kyushu University program : TBA link : TBA
Seminars Prof. Cheng Lu (Department of Physics, Nanyang Normal University, Nanyang 473061, P. R. China) Structural evolution of carbon dioxide under high pressure March 3 (Mon), 13:00-14:00 Main Research Building, Room 109 It has been a long-standing and challenging objective to stabilize Carbon (C) in hypervalent state and bonded with nonmetallic elements. Most of the works so far focused on synthesizing organic molecules with high coordination number of C. Equipped with an efficient structure search method, we take carbon dioxide (CO2) solid as a prototype system and study the evolution of its structure under high pressure. Our results show that although undertaking many structural transitions under pressure, CO2 is quite resistive to structures with C beyond 4-fold coordination. For the first time, we are able to identify two 6-fold structures of CO2 solid with Pbcn and Pa-3 symmetries that become stable at pressures close to 1TPa. Both structures consist of network of C?O octahedron, showing hypervalence of the central C atoms. The C?O bond length varies from 1.30 to 1.34 A at the 4-fold to 6-fold transition, close to the C?O distance in the transition state of a corresponding SN2 reaction. Our results provide a good measure of the resistivity of C toward forming hypervalent compounds with nonmetallic elements and of the barrier of reaction involving C-O bonds. [1] Cheng Lu et al., J. Am. Chem. Soc., 2013, 135 (38), pp 14167?14171
Seminars Stefano Gandolfi (Los Alamos National Laboratory) Microscopic Calculations of Homogeneous and Inhomogeneous Neutron Matter 15:00-, Feb. 26, 2014 RIBF Hall (rm.201), RIBF bldg.2F http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1425
Workshops RIKEN-OIST Mathphys Workshop Room B503, Lab 1, Main Campus, Okinawa Institute of Science and Technology Graduate University (OIST) https://sites.google.com/site/oistrikenjointworkshop2014/
Seminars Lembit Sihver (Chalmers Univ. of Technology, Sweden) Charged Particle Transport Simulations for Radiotherapy and Space Dosimetry Feb. 6, 2014, 13:30 RIBF Hall (rm.201), RIBF bldg. 2F
Seminars Dr. Daoyi Dong, School of Engineering and Information Technology, UNSW Canberra at the Australian Defence Force Academy, Australia Quantum State Tomography via Linear Regression Estimation Wednesday, January 15, 2014, 16:00- Main Research Building Seminar room 433 (located in the Fourth Floor)
Seminars Dr. Sangchul Oh, University at Buffalo, The State University of New York, USA Cycloid on a Bloch Sphere Monday, January 13, 2014, 16:00- Main Research Building Seminar room 435-437 (located in the Fourth Floor)
Workshops 非平衡物理、異分野の集い。--- Interdisciplinary mini-workshop on nonequilibrium physics --- December 7 - 8, 2013 Kyoto university (Room 525, Bldg. No. 5, Faculty of Science) http://ribf.riken.jp/~hidaka/workshop/iwnp.html
Seminars Mr. George Knee, Department of Materials, University of Oxford, U.K. Weak values and quantum estimation Dec. 2nd, Monday, 2013, 14:00 5F seminar room (535-537), Main Research Bldg. I will discuss some of the recent laboratory applications of Aharonov et al's 'Time-Symmetric Quantum Mechanics' . In particular I will argue that weak-value amplification, a prominent effect arising through postselection, is of no fundamental advantage over standard techniques for a number of information processing tasks, even in the presence of noise.
Seminars Dr. Wei Ku (Brookhaven National Laboratory, USA) Can high-Tc superconductivity be an entirely different beast under strong correlation? Nov. 26 (Tuesday) 16:00~17:30 Main Research Building, room #124,126 After decades of intensive research, the fundamentals of high-Tc superconductivity remain elusive. In this talk, I will discuss issues related to the strongly correlated behavior in modern high-Tc superconductors, including the Fe-based superconductors and the cuprates. For Fe-based superconductors, the rich spin/orbital correlation will be addressed, and the effects of the disordered chemical impurities be examined. For the cuprates, a strong-binding picture will be presented to explain the recently found doping independence of the superconducting gap, and to demonstrate the formation of the superconducting dome with d-wavy superfluid, the glassy electronic structure and the suppression of the Nerst signal at low doping.
Seminars Prof. Andrew Cleland, Department of Physics, University of California Santa Barbara, U.S. Coupling microwaves and light Nov. 25, Monday, 2013 13 : 30 - 15 : 00 5F seminar room (535-537), Main Research Bldg.
Seminars Prof. Jing Lu, Hunan Normal University Single-photon router: Coherent Control of multi-channel scattering for single-photons with quantum interferences Nov. 22, Friday, 2013 14:00-15:00 5F seminar room (535-537), Main Research Bldg. We propose a single-photon router using a single atom with an inversion center coupled to quantum multichannels made of coupled-resonator waveguides. It is found that the spontaneous emission of the atom is used to redirect single photons from one quantum channel into another. The on-demand classical field perfectly switches-off the single-photon routing due to the quantum interference in the atomic amplitudes of optical transitions. Total reflections in the incident channel are due to the photonic bound state in the continuum. Two virtual channels, named as scatter-free and controllable channels, are found, which are coherent superpositions of quantum channels. Any incident photon in the scatter-free channel is totally transmitted. The propagating states of the controllable channel are orthogonal to those of the scatter-free channel. Single photons in the controllable channel can be perfectly reflected or transmitted by the atom. References: e-print arXiv: 1310.7286 http://arxiv.org/abs/1310.7286
Seminars Dr. Neill Lambert, RIKEN Photon mediated transport in Hybrid QED Nov. 22, Friday, 2013 11:00-12:00 3F Room (315), Main Research Bldg. I explore photon-mediated transport processes in a hybrid circuit-QED structure consisting of two double quantum dots coupled to a common microwave cavity. Under suitable resonance conditions, electron transport in one double quantum dot is facilitated by the transport in the other dot via photon-mediated processes through the cavity. We calculate the average current in the quantum dots, the mean cavity photon occupation, and the current cross-correlations using a recursive perturbation scheme that allows us to include the influence of the cavity order-by-order in the couplings between the cavity and the quantum dot systems. Within this framework we can clearly identify the photon-mediated processes in the transport.
Seminars Dr. Sergey Shevchenko, B. Verkin Institute for Low Temperature Physics (ILTPE) Dynamical behavior of the driven qubit-resonator system Nov. 21, Thursday, 2013 13 : 30 - 15 : 00 5F seminar room (535-537), Main Research Bldg. In my talk I would like to report about recent activity related to the system with superconducting qubits coupled to classical nanomechanical resonator [1] or quantum transmission-line resonator [2]. In Ref. [1] we have studied how the strongly driven superconducting qubit can be probed by a nanomechanical resonator (direct Landau-Zener-Stuckelberg interferometry) and, vice versa, how position of the nanomechanical resonator can be defined by the qubit's state (inverse interferometry). There, in relation to the experimental realization, we considered the situation when the resonator is slow in comparison to qubit's dynamics. When the frequency of the resonator is compared to the qubit's characteristic frequency, the convenient tool for the description of the coalesced atom and field is the notion of dressed states. In our recent work [2] we considered particular case when the transmission-line resonator was driven at two harmonics, where we were interested how one of the signals can be changed by another signal via qubit. References: [1] S. N. Shevchenko, S. Ashhab, and F. Nori, Inverse Landau-Zener-Stuckelberg problem for qubit-resonator systems, Phys. Rev. B 85, 094502 (2012). [2] S. N. Shevchenko, G. Oelsner, Ya. S. Greenberg, P. Macha, D. S. Karpov, M. Grajcar, A. N. Omelyanchouk, and E. Il’ichev, Amplification and attenuation of the transmitted signal by doubly-dressed states, arXiv:1309.2619, submitted to Phys. Rev. B. [1] http://prb.aps.org/pdf/PRB/v85/i9/e094502 [2] http://arxiv.org/pdf/1309.2619v1.pdf
Seminars Mr. Martin Leib, Technische Universitat at Muenchen Strongly Interacting Many Body Physics with Circuit Quantum Electrodynamics Networks Nov. 21, Thursday, 2013 11:00-12:00 3F Room (315), Main Research Bldg. In its infancy circuit quantum electrodynamics (cQED) has quickly started reproducing fundamental quantum optical experiments, e.g. observation of vacuum rabi oscillations in frequency and time domain, with unprecedented cooperativity. This was possible because of the large coupling strength of the quasi one-dimensional microwave field of the superconducting transmission line resonators to the macroscopic dipole moment of superconducting qubits. Since then cQED has matured to a discipline of experimental physics capable of performing fundamental quantum information tasks and is currently on the verge of crossing the border between few- to many body physics [1]. This opens up a exciting realm of completely new physical phenomena. Because of the ubiquitous influence of the electromagnetic environment however the number of microwave photons is not conserved which separates cQED systems from other quantum simulators involving atoms, e.g. cold atoms in optical latices. Instead cQED is ideally suited for exploring quantum many-body physics in the driven dissipative regime where the interplay of constant injection of microwave photons and the unpreventable loss of microwave photons into the electromagnetic environment generates a whole new class of steady- but not equilibrium states. I am presenting our ideas for the simulation of many body physics in the circuit QED framework after a short introduction into the world of circuit QED and many body physics. New J. Phys. 12 093031 New J. Phys. 14 075024 Phys. Scr. 2013 014042 PRL 110 163605
Seminars Prof. Su Yi, Institute of Theoretical Physics, Chinese Academy of Sciences Ultracold Fermi gases with resonant dipole-dipole interaction Nov. 20, Wednesday, 2013 14:00-15:00 5F seminar room (535-537), Main Research Bldg. In this talk, I will report the studies on the superfluid phases of an ultracold Fermi gases with resonant dipole-dipole by the standard mean-field theory. I will show that, in contrast to the crossover from BEC to BCS superfluid in Fermi gases with isotropic interactions, resonant dipolar interaction leads to two completely different BEC phases of the tight-binding Fermi molecules on both sides of the resonance, which are characterized by two order parameters with distinct internal symmetries. Near the resonances, these two competitive phases can coexist, and an emergent relative phase between the two order parameters spontaneously breaks time-reversal symmetry. I will also discuss the experimental observation of these phases via momentum resolved rf spectroscopy. Reference: T. Shi, S.-H. Zou, H. Hu, C.-P. Sun, and S. Yi, Phys. Rev. Lett. 110, 045301 (2013). http://prl.aps.org/abstract/PRL/v110/i4/e045301
Seminars Prof. Fabio Marchesoni, University of Camerino and INFN Diffusion of two-sided Janus particles inside narrow channels Nov. 18, Monday, 2013 16:00-17:00 4F seminar room (424-426), Main Research Bldg. Directed Brownian transport in asymmetric narrow channels of various geometries [1] is discussed in the presence of different external biases, including periodic drives and other time correlated energy sources. High-efficiency autonomous ratcheting is obtained [2] by employing active (or self-propelling) Brownian particles (e.g., Janus particles) both in a dilute solution and in binary mixtures. In the latter case a small fraction of active Brownian particles suffices to force collective transport of the entire mixture along the channel. In the case of elongated (rod-like) Janus particles driven in channel transport properties selectively depend on the particle shape; under certain conditions giant negative mobility is observed [3]. References [1] P. Hanggi and F. Marchesoni, Rev. Mod. Phys. 81, 387 (2009) [2] P.K. Pulak, V.R. Misko, F. Marchesoni, F. Nori, Phys. Rev. Lett. 110, 268301 (2013) [3] work in preparation
Seminars Prof. Han Pu, Rice University Cavity-Assisted Spin-Orbit Coupling in Cold Atoms Nov. 18, Monday, 2013 14:00-15:00 4F seminar room (424-426), Main Research Bldg. Synthetic spin-orbit coupling (SOC) in cold atoms has been one of the most active fields over the past few years. In experiment, SOC is realized by Raman coupling two atomic hyperfine states. In this work, we consider the effect of SOC in ultracold atoms induced by a quantized light field inside an optical cavity, where the back-action from the atom to the cavity light field plays an essential role. We show that the atom-photon feedback induces intriguing properties in this system. References: arXiv:1309.4369 http://arxiv.org/abs/1309.4369
Seminars By Prof. Hui Jing, HeNan Normal University Optomechanics with a multi-component quantum gas Nov. 18, Monday, 2013 11:00-12:00 4F seminar room (424-426), Main Research Bldg. I will talk about cavity optomechanical control of a multiple atomic Bose condensate. Firstly, for a three-component (spin-1) gas I will show how to get coherent optical control of a quantum rotor (opto-rotational control of the spin gas) especially quantum squeezing of the rotor gas; secondly, for a two-species mixture, I will show how to get linearly coupled quantum oscillators by tuning atomic scattering lengths. By applying a time-varying Feshbach magnetic field, it is also possible to observe the optomechanical geometric (Berry's) phase or even phase transition in a cavity quantum gas. References: H. Jing, D. S. Goldbaum, L. Buchmann, and P. Meystre, Phys. Rev. Lett. 106, 223601 (2011). H. Jing, X. Zhao, and L. Buchmann, Phys. Rev. A 86, 065801 (2012). S. Singh, H. Jing, E. M. Wright, and P. Meystre, Phys. Rev. A 86, 021801 (2012). L. F. Buchmann, H. Jing, C. Raman, and P. Meystre, Phys. Rev. A Rapid Communication 87, 031601 (2013). http://publish.aps.org/search?c%5B%5D%5Bfield%5D=author&c%5B%5D%5Bvalue%5D=H.+Jing&c%5B%5D%5Boperator%5D=AND&c%5B%5D%5Bfield%5D=abstitle&c%5B%5D%5Boperator%5D=AND&c%5B%5D%5Bfield%5D=fulltext&c%5B%5D%5Boperator%5D=AND
Workshops iTHES-HPCI Joint WS on "Nuclear equation of state with strangeness" November 11 - 15, 2013 Main research building room 213 http://www.jicfus.jp/jp/131111-15hpci/#program http://www.jicfus.jp/jp/131111-15hpci/
Seminars Prof. Bo Thide, Swedish Institute of Space Physics, Sweden Photon Angular Momentum at Radio Frequencies Oct. 31st, Thursday, 2013, 14:00 3F (315), Main Research Bldg. Photons carry not only energy and spin angular mometum (SAM) but also orbital angular momentum (OAM). I will present some results from our OAM research at low frequencies in Uppsala, Sweden, and Padua, Italy. Low-frequency OAM is a new radio technique that can provide more detail than can be obtained with methods in optics using diffractive optics element. It can be used in radio astronomy as well as in radio communication applications. Some of the fundamental physical properties of angular momentum, the related physical observables and their measurement in radio experiments will be described. New results, including experimental verification of multi-channel wireless information transfer within a given frequency bandwidth, using the topological properties of photons carrying OAM will be presented.
Seminars Prof. Tobias Brandes, Institute for Theoretical Physics, Technical University of Berlin, Germany Hardwiring a Maxwell demon Oct. 24th, Thursday, 2013, 16:00 - 17:00 4F seminar room (435-437), Main Research Bldg. We present a physical implementation of a Maxwell demon which consists of a conventional single electron transistor (SET) capacitively coupled to another quantum dot detecting its state. Altogether, the system is described by stochastic thermodynamics. We identify the regime where the energetics of the SET is not affected by the detection, but where its coarse-grained entropy production is shown to contain a new contribution compared to the isolated SET. This additional contribution can be identified as the information flow generated by the ‘‘Maxwell demon’’ feedback in an idealized limit.
Seminars Dr. Haitao Quan, School of Physics, Peking University, China Nanoscale Carnot engines Oct. 24th, Thursday, 2013, 14:00 - 16:00 4F seminar room (435-437), Main Research Bldg. *abstract (if any): We study the maximum efficiency of a Carnot engine based on a small system. It is revealed that due to the finite size of the working substance, irreversibility may arise in the thermodynamic cycle. As a result, a correction to the usual Carnot efficiency is required. This result defies the long-standing belief that the maximum efficiency of a heat engine does not depend on the details of the working substance. Furthermore, we find a general and simple expression for the maximum efficiency of heat engines. This maximum efficiency approaches the usual Carnot efficiency when the size of the working substance increases to macroscopic size. Hence our result reconcile with the traditional theories of thermodynamics in the thermodynamic limit and include it as a special case. Our study demonstrates the subtleties of thermodynamics of small systems.
Workshops Todai/Riken joint workshop on Super Yang-Mills, solvable systems and related subjects October 23 - 24 2013 Rm. 1320, Science Bldg.4, Hongo Campus, Univ. of Tokyo Recent years has seen a lot of interesting research and attempts regarding super Yang-Mills theories, solvable statistical systems, and of course, conformal field theories and their interrelations. There are many novel discoveries revealed by these efforts. It would be a good time for us to get together and share those insights with each other. This small workshop is motivated for that purpose. We hope that those who are interested in the subjects can participate and engage in active discussions at our workshop. Organizers: Yutaka Matsuo (Tokyo), Tsukasa Tada (Riken) Speakers: K. Ito (T.I.T.), H. Itoyama (Osaka C.U.), V. Kazakov (E.N.S.), I. Kostov (Saclay), Y. Matsuo (Tokyo), K. Ohmori (Tokyo), T. Okuda (Tokyo), D. Serban (Saclay), H. Shimada (OIQP), E. Sobko (ENS), F. Sugino (OIQP), T. Tada (Riken), M. Taki (Riken), S. Terashima (YITP) http://susy.theoreticalscience.info
Seminars Dr. Sahin Kaya Ozdemir, Washington University in St. Louis, USA Parity-time symmetric whispering gallery optical microcavities Oct. 22nd, Tuesday, 2013, 14:00 - 16:00 5F seminar room (535-537), Main Research Bldg. Parity (space-)-time- (PT-) symmetry- an abstract notion and a mathematical tool in quantum field theory has emerged as a new and powerful tool to design and fabricate artificial materials (meta-materials) with unique properties that cannot be found or attained in natural materials having only gain or loss. PT-symmetric Hamiltonian systems have attracted great interest following the work of Bender and Boettcher [1] who showed that the eigenvalue spectra of non-Hermitian Hamiltonians ?†≠ ? can still be entirely real if they respect PT-symmetry, PT? = ?PT. The interest was further fueled by the first demonstration of PT-symmetry in optics [2]. Systems respecting the PT-symmetry are interpreted as non-isolated physical systems with carefully balanced loss and gain. When the PT symmetry is broken, such systems undergo phase transitions which are reflected as the emergence of complex eigenvalues. In the broken-symmetry phase, such systems are expected to exhibit several striking properties [3] such as field localization, unidirectional invisibility, enhanced or reduced reflections, nonreciprocal light transmission, loss induced transparency and co-existing coherent-perfect-absorber and laser. Some of these features have been experimentally demonstrated in optical domain using coupled waveguides with gain and loss. Up to date, all optical experiments have been performed using waveguide structures with dimensions ranging from a few centimeters to hundreds of meters. In this talk, after giving a brief introduction to whispering gallery mode (WGM) optical microcavities and PT-symmetric concepts, I will discuss the PT-symmetric concepts in optics and report the first demonstration of PT-symmetry in on-chip WGM microcavities [4]. I will also show the first observation of nonreciprocal light transmission (an optical diode) in the broken PT-symmetry phase using these microcavities. We envisage PT-symmetric microcavities to play significant role for building unconventional optical devices to manipulate light and control energy flow as well as to become a platform for realizing co-existing coherent perfect absorber (CPA) and lasers. [1] S. Boettcher, C. M. Bender, Real spectra in non-Hermitian Hamiltonians having PT symmetry. Phys. Rev. Lett. 80, 5243 (1998). [2] C. E. Ruter, K. G. Makris, R. El-Ganainy, D. N. Christodoulides, M. Segev & D. Kip, Observation of parity-time symmetry in optics. Nature Phys. 6, 192 (2010). [3] A. Regensburger, C. Bersch, M.-A. Miri, G. Onishchukov, D. N. Christodoulides & U. Peschel, Parity?time synthetic photonic lattices. Nature 488, 167 (2012). [4] B. Peng, S. K. Ozdemir, F. Lei, F. Monifi, M. Gianfreda, G. L. Long, S. Fan, F. Nori, C. M. Bender & L. Yang. Nonreciprocal light transmission in parity-time-symmetric whispering-gallery microcavities. arXiv:1308.4564
Seminars N. Iizuka (ithes-phys team), P. Ghosh (ithes-cond team) October 15 (Tuesday) room 433 (main building) 15:00-16:00 N. Iizuka (ithes-phys team) "Applications of the gauge/gravity duality to condensed matter physics" 16:00-17:00 P. Ghosh (ithes-cond team) "Study of photosynthesis and other biological phenomena using methods of statistical mechanics and condensed matter physics”
Seminars Professor Yoshitaka Tanimura (Department of Chemistry, Kyoto University) October 10 Thursday: Theory of Reduced Hierarchy equations of motion 1st lecture: 1:30 to 3 pm Break: 3 to 4 pm 2nd lecture: 4 pm to 5:30 Location: 435 and 437 (newer seminar room in the 4^th floor of the Main Research building) October 11 Friday: Theory of Multidimensional Spectroscopies 1st lecture: 1:30 to 3 pm Break: 3 to 4 pm 2nd lecture: 4 pm to 5:30 Location: the large seminar room located right on top of the large cafeteria. The Friday lectures are about nonlinear response of systems, and related to the first lectures. The Power Point lecture notes for the above subjects are in his homepage: http://theochem.kuchem.kyoto-u.ac.jp/members/tanimura.htm
Seminars Prof. Kenneth M. Merz Jr. Director, Institute for Cyber Enabled Research (iCER), Joseph Zichis Chair in Chemistry Department of Chemistry, Department of Biochemistry and Molecular Biology, Michigan State University, USA Free Energies from a Molecular Printing Press September 26 (Thursday), 2013 16:00-18:00 RIKEN Wako Campus, Main research building 4F 435/437 Docking (posing) calculations coupled with binding free energy estimates (scoring) are a mainstay of structure-based drug design. Docking and scoring methods have steadily improved over the years, but remain challenging because of the extensive sampling that is required, the need for accurate scoring functions and challenges encountered in accurately estimating entropy effects. This talk addresses the use of ensemble principles to directly address these issues and, thereby, accurately estimate protein-ligand binding free energies. In particular, we analytically demonstrate that sampling reduces computed binding free energy uncertainties and then highlight several methods that incorporate these concepts. For example, the moveable type method, employs an elegant approach to generate the necessary ensembles by using a “binned” pairwise knowledge-based potential combined with atom pair probabilities extracted from known protein-ligand complexes. This allows us to rapidly compute the ligand, protein and protein-ligand (inclusive of solvation effects) ensembles which then can be used to directly estimate protein-ligand binding free energies using basic statistical mechanical principles. This approach improves the quality of the potential (scoring) function by reducing computational uncertainty, sampling phase space in one shot and accurately incorporating entropy effects. This allows us to compute binding free energies rapidly, accurately and yields molecular poses at a minimal computational cost relative to currently available methods based on statistical mechanics.
Seminars Mr. Pavel Maksimov, Institute for Theoretical and Applied Electrodynamics, Russia, Moscow Institute for Physics and Technology, Russia Localized electron states near the graphene armchair edge Sep. 13th, Friday, 2013, 14:00 - 15:00 4F seminar room (435-437), Main Research Bldg. For a finite graphene sheet there are two distinct types of edge: zigzag and armchair. Zigzag edge is known for more than fifteen years [1] to be able to support localized electron states and bind electrons: there is a non-dispersive single-electron band localized near the edge. But it is generally believed that the armchair edge does not support such localized states [2]. This result is a consequence of two assumptions: that (i) the hopping integrals between nearest-neighbor carbon atoms both are the same in the bulk of the sample and near the edge, and that (ii) no non-carbon atoms or functional groups are attached to the carbon atoms on the edge. In principle, either of these two conditions may be violated (for instance, Fig.1 shows the situation where non-carbon radicals R passivate the unpaired carbon chemical bonds at the edge). Effectively, deviations from (i) or (ii) lead to new boundary conditions for the electron wave function. As a result, in a certain parameter range localized states emerge on the armchair edge. We demonstrate that, depending on which condition is violated, properties of the localized band differ. Namely, if the hopping integral at the edge is modified [that is, when (i) is invalid], the eigenenergy of the localized states has pronounced dependence on the electron momentum along the edge, and the edge-state branches appear in electron-hole symmetric pairs. At the same time, when graphene π-orbitals hybridize with the non-carbon orbitals near the edge [condition (ii) is no longer true, see Fig.1], the resultant pair of localized edge bands is nearly flat, with no electron-hole symmetry. These states may be detected experimentally with the help of STM. References: [1] K. Nakada, M. Fujita, G. Dresselhaus, and M.S. Dresselhaus, Phys. Rev. B 54 (1996) 24. [2] Y. Zhao, W. Li, and R. Tao, Physica B: Condensed Matter 407 (2012) 4.
Seminars Dr. Jacob Biamonte, ISI Foundation, Italy Universal adiabatic quantum computation Aug. 27th, Tuesday, 2013, 14:00 4F seminar room (435-437), Main Research Bldg. The complexity of finding the ground state energy of interacting spins unites computer science and physics in a profound way. On the one hand, it ties computational complexity directly to solving a problem of practical importance regularly faced in several areas of modern physics. On the other hand, measuring the ground state energy gap of such a physical spin system would enable one to solve such problems directly. How then might we extend current adiabatic computing architectures being developed for practical calculations in a way to also enable them to perform universal quantum computation?
Seminars Dr. Pulak Kumar Ghosh, Quantum Condensed Matter Research Group, CEMS, RIKEN Quantum effects in energy and charge transfer in a wheel-shaped artificial photosynthetic complex Aug. 26th, Monday, 2013, 19:00 4F seminar room (435-437), Main Research Bldg. We investigate the quantum dynamics of energy and charge transfer in a wheel-shaped artificial photosynthetic antenna-reaction center complex. This complex consists of six light-harvesting pigments and an electron-acceptor fullerene. To describe quantum effects on a femtosecond time scale, we derive a set of modified Redfield equations taking into account the time evolution of the off-diagonal elements of the density matrix. We show that the energy of the initially-excited antenna chromophores is efficiently funneled to the porphyrin-fullerene reaction center, where a charge-separated state is set up in a few picoseconds, with a quantum yield of the order of 95 %. In the single-exciton regime, with one antenna chromophore being initially excited, we observe quantum beatings of energy between two resonant antenna pigments with a decoherence time of ~ 100 fs. We also analyze the double-exciton regime, when two porphyrin molecules involved in the reaction center are initially-excited. In this regime we obtain pronounced quantum oscillations of the charge on the fullerene molecule with a decoherence time of about 20 fs (at liquid nitrogen temperatures). These results show a way to directly detect quantum effects in artificial photosynthetic systems.
Seminars Dr. Robert Johansson, Quantum Condensed Matter Research Group, CEMS, RIKEN Engineered quantum mechanics with nano-electronics Aug. 26th, Monday, 2013, 17:00 4F seminar room (435-437), Main Research Bldg. Nanoelectrical and nanomechanical devices can be engineered to behave quantum mechanically at cryogenic temperatures. With different device designs, a rich variety of quantum systems can be implemented, including artificial atoms, resonators, controllable and tunable coupling and high-fidelity measurements. The intrinsic nonlinearities and dissipation-free nature of Josephson junctions makes superconducting electrical circuits an ideal test-bed for experiments on analogues and simulations of quantum mechanical phenomena from different fields of physics. In particular, many problems from quantum optics, atomic physics, quantum field theory, and solid-state physics can be explored in nanoelectrical circuits, and often with significant advantages. Here I will first give a brief overview of recent progress in quantum electronics and how these devices can be used as quantum simulators. I will continue with a summary of a few selected projects that I have worked on, including nanoelectrical implementations of the Dynamical Casimir effect, single-atom lasing and Landau-Zener-Stuckelberg interferometry. I will also briefly describe a computational project where we have developed a highly versatile framework for quantum dynamics simulations that is suitable for computational analysis of the evermore complex nanoelectrical devices.
Seminars Dr. Mark Everitt, Loughborough University, UK Enhanced engineering of Schrodinger cat states. Aug. 8th, Thursday, 2013, 13:30 4F seminar room (435-437), Main Research Bldg. We look at engineering macroscopically distinct superpositions of states (Schrodinger cat) in fields, ensembles of spins and SQUIDs and, for selected examples, the effects of decoherence may be mitigated or used to advantage (note we will also make use of a new spin Wigner function).
Seminars Dr. Justin Dressel, Quantum Condensed Matter Research Group, CEMS, RIKEN Weakly Measuring Observables with Generalized Eigenvalues Jul. 30th, Thursday, 2013, 14:00 4F seminar room (435-437), Main Research Bldg. The common wisdom in quantum mechanics is that observables are intrinsically defined by projective measurements and eigenvalues. We challenge this wisdom by demonstrating a general algebraic formalism for completely measuring observables using indirect detectors. We find that the eigenvalues are inappropriate when considering noisy detectors that do not make projective measurements; instead one must assign generalized eigenvalues to the accessible detector outcomes. We illustrate this procedure with a simple example: a polarization measurement using only two correlated spatial modes produced by a glass microscope coverslip. We then use this simple system to violate nonlocal Leggett-Garg inequalities by post-selecting the weakened measurements. We also revisit the "weak measurement" protocol of Aharonov et al. and solve it exactly in terms of the general formalism, showing the universality of weak values in the process.
Workshops PHENIX Workshop on Physics Prospects with Detector and Accelerator Upgrades July 29 - Aug.2, 2013 Nishina Hall, RIKEN http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1221 The PHENIX experiment has been successfully contributing to understand of our long standing questions in nuclear/ hadron physics, since the experiment was launched in 2001. Given the abundant physics we have addressed so far, we have been proposing to build a electron-ion collider at RHIC as a further step on addressing still unexplored issues in the field. This work fest is an opportunity to introduce this attractive project widely to east Asian nuclear physicists who are not necessarily be involved in current PHENIX/RHIC program and may prompt the interest on this topic. This work fest is sponsored by Radiation Labororatory and iTHES.
iTHES mini-workshop on Exploration of hidden symmetries in atomic nuclei July 27th, 2013 RIKEN Symmetry is a key element of discovery of fundamental principles in a variety of physical systems. The ubiquitous quasi-degeneracy between single-particle orbitals (n-1, l+2, j=l+3/2) and (n, l, j=l+1/2) indicates a kind of hidden symmetry in atomic nuclei which was found in 1960s by two groups (Arima, Harvey, and Shimizu; Hecht and Adler). This is the so-called pseudospin symmetry (PSS). Both the splitting of spin doublets and pseudospin doublets play critical roles in the evolution of magic numbers in exotic nuclei discovered by modern spectroscopic studies with RIB facilities. Since the PSS was recognized as a relativistic symmetry in 1990s, it has been suggested that this symmetry is relevant to the QCD sum rule and shares the same kind of origin of the spin symmetry (SS) in hadrons spectra. During the past decade, many special features were investigated and many new concepts were introduced. In addition, the semi-classical theory for shell structure has been extensively developed. In this mini-workshop, we will exchange ideas on these recent progresses and deepen our understanding of the conservation and breaking of SS and PSS in a quantitative and interdisciplinary way. Possible topics include PSS in deformed nuclei, exact PSS in resonant states, SS in anti-nucleon spectra, PSS within supersymmetric quantum mechanics, shell structures in finite quantum systems in terms of periodic orbits, and so on. Organizers: Haozhao Liang (RIKEN) Jie Meng (Peking U., China) Takashi Nakatsukasa (RIKEN) Speakers: Kenichiro Arita (Nagoya Institute of Technology) Joseph N. Ginocchio* (Los Alamos National Lab, US) Ikuko Hamamoto (RIKEN) Stefan Typel* (GSI, Germany) Shan-Gui Zhou (Institute of Theoretical Physics, CAS, China) https://indico2.riken.jp/indico/conferenceDisplay.py?confId=1237
Seminars Dr. T. Kanazawa (Univ. Tokyo) Symmetries and effective field theories in QCD July 26 (Fri.) 10:00am-11:00am room 435-437, main building (4th floor) The first part of this talk is planned to be a rudimentary introduction to gauge theories and strong interactions. In the second part I will review my own contributions to understanding dense QCD-like theories through effective field theories and matrix models.
Workshops Current challenges in the Physics of Neutron Star July 5 (Fri.) 2013, 13:30- room 433, Main building 13:30-14:15 Mark Alford (Washington U.) "Hybrid stars and the quark matter equation of state" 14:15-14:45 Kota Masuda (Tokyo/RIKEN) "Hadron-Quark Crossover and Massive Hybrid Stars" 14:45-15:00 Break 15:00-15:45 Thomas Hell (Munich) "How neutron stars constrain the nuclear equation of state" 15:45-16:15 Nobutoshi Yasutake (Chiba-tech.) "TBA" 16:15- Free discussions
Seminars Dr. Konstantin Bliokh, A. Usikov Institute for Radiophysics & Electronics, National Academy of Sciences of Ukraine Electron vortex beams in a magnetic field: A new twist on Landau levels and Aharonov-Bohm states Jul. 4th, Thursday, 2013, 13:30 4F seminar room (435-437), Main Research Bldg. We examine the propagation of the recently-discovered electron vortex beams in a longitudinal magnetic field. We consider both the Aharonov-Bohm configuration with a single flux line and the Landau case of a uniform magnetic field. While stationary Aharonov-Bohm modes represent Bessel beams with flux- and vortex-dependent probability distributions, stationary Landau states manifest themselves as non-diffracting Laguerre-Gaussian beams. Furthermore, the Landau-state beams possess field- and vortex-dependent phases: (i) the Zeeman phase from coupling the quantized angular momentum to the magnetic field and (ii) the Gouy phase, known from optical Laguerre-Gaussian beams. Remarkably, together these phases determine the structure of Landau energy levels. This unified Zeeman-Landau-Gouy phase manifests itself in a nontrivial evolution of images formed by various superpositions of modes. We demonstrate that, depending on the chosen superposition, the image can rotate in a magnetic field with either Larmor, cyclotron, or zero frequency. At the same time, its centroid always follows the classical trajectory, in agreement with the Ehrenfest theorem. Our results open up an avenue for the direct electron-microscopy observation of fundamental properties of free quantum electron states in magnetic fields.
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