2025年度セミナー
今年度前期は水曜日午後１時３０分からセミナーを行います。 このセミナーの他にも、毎週木曜日１５時から本郷理学部４号館３階１３２０号室にて行われる統計力学セミナーにも参加しています。
| 日程 | 時間 | 講演者 | 演題・要旨 |
| 05月08日(木) Wed, May 8 |
14:00 |
法橋顕広（Hokkyo Akihiro）さん （東大 / U. Tokyo） |
Rigorous Test for Quantum Integrability and Nonintegrability | 要旨
第０１回
講師：法橋顕広（Hokkyo Akihiro）さん（東大 / U. Tokyo）日時：２０２５年０５月０８日（木）１４時００分〜 / Thursday, 08th May 2025, 14:00 JST -
演題：Rigorous Test for Quantum Integrability and Nonintegrability
要旨：The integrability of a quantum many-body system, which is characterized by the presence or absence of local conserved quantities, drastically impacts the dynamics of isolated systems, including thermalization. Nevertheless, a rigorous and comprehensive method for determining integrability or nonintegrability has remained elusive. In this talk, we address this challenge by introducing rigorously provable tests for integrability and nonintegrability of quantum spin systems with finite-range interactions. Our results significantly simplify existing proofs of nonintegrability, such as those for the S=1/2 Heisenberg chain with nearest-and next-nearest-neighbor interactions, the S=1 bilinear-biquadratic chain and the S=1/2 XYZ model in two or higher dimensions. This work also offers a partial resolution to the long-standing conjecture that integrability is governed by the existence of local conserved quantities with small support. Our framework ensures that the nonintegrability of one-dimensional spin systems with translational symmetry can be verified algorithmically, independently of system size.