Mississippi State University

报告人简介：

叶锦武教授是美国耶鲁大学理论物理博士。他现在是美国密西西比州立大学教授. 叶教授主要研究领域是强相互作用的电子、玻色子、自旋、光子等的合作现象和量子或拓扑相变理论。他的研究还涉及超对称性破缺，共形场论和各种量子或拓扑相的量子引力对偶。His two most recent research directions are on：(1) Novel Quantum, topological Phases, phase transitions driven by interactions in various spin-orbit coupled systems. (2) quantum chaos and quantum information scramblings in cavity QED systems or in Sachdev-Ye-Kitaev models.

报告摘要：

In this colloquium, we first review the two completely different approaches： (1) Renormalization groups or $1/N $ expansions which study the ground states and the low energy excitations. (2) Random matrix theory which study the statistical properties of the excited states. Then we apply both approaches to study qunatum chaos and quantum information scramblings in two different modles:  (1) Sachdev-Ye-Kitaev models which may have a bulk quantum black holes in an asymptotically  $ Ads_2 $ space.  (2) $ U(1)/Z_2 $ Dicke models which describe $ N $ qubits interacting with photons inside a cavity.  Then we discuss possible intimate connections between the two different theoretical approaches and the two different models.

1. Jinwu Ye, Two indices  Sachdev-Ye-Kitaev model,  ArXiv：1809.0667, substantially revised version 2 to be put on ArXiv soon.

2. Yu Yi-Xiang, Fadi Sun,  Jinwu Ye and WuMing Liu, A new universal ratio in Random Matrix Theory and  Random matrices and quantum analog of Kolmogorov-Arnold-Moser (KAM) theorem in hybrid Type-I and Type-II Sachdev-Ye-Kitaev models,  ArXiv：1809.07577. Accepted in Phys. Rev. B.

3. Fadi Sun, Yu Yi-Xiang, Jinwu Ye and WuMing Liu,  Classifications of quantum chaos in colored Sachdev-Ye-Kitaev models, arXiv:1903.02213. in press in Phys. Rev. D.

4. Fadi Sun and Jinwu Ye,  Periodic Table of SYK and supersymmetric SYK , arXiv:1905.07694.

5. Yu Yi-Xiang, Jinwu Ye and CunLin Zhang,  Photon Berry phases, Instantons, Quantum chaos and quantum analog of Kolmogorov-Arnold-Moser (KAM) theorem in the $ U(1)/Z_2 $ Dicke models, arXiv:1903.02947,  substantially revised version 2 to be put on ArXiv soon.

邀 请 人：刘伍明（电话：8264 9249）

联 系 人：李园园（电话：8264 9364）