皆様 Dear All
＊本案内は複数のメーリングリストにお送りしております。重複して受け取られました方は何卒ご容赦下さい。
sorry for multiple e-mails.
羽田野（東京大学生産技術研究所）です。
英語での統計力学セミナーのご案内をお送り致します。是非ご参加下さい。
オンサイトで行いますが、オンライン参加をご希望の方は以下にご登録ください。
ゼミナー前にzoomリンクをお送りします。
forms.gle/YN22NTx3zAP31NQ17
This is Naomichi Hatano from the Institute of Industrial Science, The University of Tokyo.
We will have a StatPhys seminar in English as follows. It will be an onsite one, but
if you wish to join online, register to the following site.
We will send you a zoom link before the seminar.
forms.gle/YN22NTx3zAP31NQ17
以下で今後のセミナーの予定をご確認頂けます。
sites.google.com/view/statphys-seminar/%E3%83%9B%E3%83%BC%E3%83%A0
You will be able to check the announcement of upcoming seminars in the following web site:
sites.google.com/view/statphys-seminar/%E3%83%9B%E3%83%BC%E3%83%A0
日時 Date and Time: ２０２３年６月３０日（水）Friday, June 30, 2023
場所 Onsite place：東京大学 本郷キャンパス 理学部1号館206教室 (Room No. 206, Science 1st Bldg., Hongo Campus, The University of Tokyo)
道程 Access www.u-tokyo.ac.jp/campusmap/cam01_07_01_j.html
No. 101 of www.u-tokyo.ac.jp/content/400020145.pdf
講師 Speaker 濱崎立資さん（理研） Dr. Ryusuke Hamazaki (RIKEN)
演題 Title: Universality, breakdown, and timescale of thermalization in isolated quantum systems
要旨：Abstract:
How isolated quantum systems relax to thermal equilibrium is the fundamental problem in quantum statistical mechanics [1]. While local observables in generic systems are believed to thermalize after long time via the eigenstate thermalization hypothesis (ETH) [2], to what extent the ETH universally holds is still an open question; indeed, recent studies show that thermalization breaks down by various mechanisms. Furthermore, understanding timescale for thermalization is another challenge beyond the theory of the ETH.
In this talk, we address universality, breakdown, and timescale of thermalization in isolated quantum systems. We first show our numerical verification of the universality of the ETH for realistic quantum many-body systems. We introduce few-body random matrix ensembles to model realistic systems and show that the ETH holds for most of them unless the range of the interactions is too long [3].
We then discuss some new mechanisms that break the ETH in non-integrable systems. We start with high-dimensional quantum Ising models with a weak transverse field. Despite its non-integrability, we discover that the domain-wall conservation law in the effective model leads to the Hilbert-space fragmentation, a recently found mechanism for the absence of thermalization [4]. We next show how general discrete symmetries should break the ETH for a certain class of non-local observables, especially emphasizing the case where higher-form symmetries exist [5].
If time allows, we discuss quantum speed limits useful for the macroscopic transitions, such as macroscopic transport of atoms, which are relevant for timescales of thermalization from inhomogeneous initial states. Employing the local conservation law of probability, we derive quantum speed limits that lead to reasonable timescales for macroscopic transitions [6].
[1] J. Eisert, M. Friesdorf, and C. Gogolin, Nat. Phys. 11, 124 (2015).
[2] M. Rigol, V. Dunjko, M. Olshanii, Nature 452, 854 (2008)
[3] S. Sugimoto, R. Hamazaki, and M. Ueda, Phys. Rev. Lett. 126 (12), 120602 (2021) <doi.org/10.1103/PhysRevLett.126.120602>; Phys. Rev. Lett. 129 (3), 030602 (2022) <doi.org/10.1103/PhysRevLett.129.030602>.
[4] A. Yoshinaga, H. Hakoshima, T. Imoto, Y. Matsuzaki, and R. Hamazaki, Phys. Rev. Lett. 129 (9), 090602 (2022) <doi.org/10.1103/PhysRevLett.129.090602>.
[5] O. Fukushima and R. Hamazaki, arXiv:2305.04984 (2023) <doi.org/10.48550/arXiv.2305.04984>.
[6] R. Hamazaki, PRX Quantum 3 (2), 020319 (2022) <doi.org/10.1103/PRXQuantum.3.020319>.
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Naomichi Hatano
Institute of Industrial Science, University of Tokyo
Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8574, JAPAN
Phone: +81-4-7136-6961
Fax: +81-4-7136-6978
hatano-lab.iis.u-tokyo.ac.jp/hatano/
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