报告一：热力学的几何与信息物理：有限时间过程及其关联

主讲人：孙昌璞教授，中国科学院院士，中国工程物理研究院研究生院创院院长、教授

报告二：Rise and fall of high-Tc superconductivity in pressurized bilayer nickelate

主讲人：李伟研究员，中科院理论物理研究所

时  间：2024年12月12日（周四）下午14:00-17:00

主持人: 西湖大学理学院物理系讲席教授吴从军&物理系PI严正博士

地  址：西湖大学云谷校区E10-201

语  言：中文

Lecture 1

Title: 热力学的几何与信息物理：有限时间过程及其关联

Speaker: Prof. Chang-Pu Sun, Academician of Chinese Academy of Sciences & Dean, Graduate School of China Academy of Engineering Physics

Lecture 2

Title: Rise and fall of high-Tc superconductivity in pressurized bilayer nickelate

Speaker:Prof. Wei Li, Researcher, Institute of Theoretical Physics, Chinese Academy of Sciences

Time: 14:00-17:00, Thursday, December 12, 2024

Host: Prof. Congjun Wu, Chair Professor of Physics, School of Science & Prof. Zheng Yan, PI of Department of Physics, School of Science

Address: E10-201, Yungu Campus, Westlake University

Language: Chinese

主讲人 1 /Speaker 1:

孙昌璞 院士

中国科学院院士，

中国工程物理研究院研究生院创院院长、教授

Prof. Chang-Pu Sun,

Academician of Chinese Academy of Sciences，

Dean, Graduate School of China Academy of Engineering Physics

个人简介/Biography:

孙昌璞，理论物理学家，中国科学院院士，发展中国家科学院院士，中国工程物理研究院研究生院创院院长、教授。本科毕业于东北师大物理系，于南开大学获博士学位。曾任东北师大教授，中科院理论所研究员。获得过国家自然科学二等奖和美国ISI“经典引文奖”等奖励以及全国先进工作者等荣誉称号。他长期组织参与我国物理学科战略规划工作（基金委和科学院十三五发展规划的秘书组组长和十四五规划的战略组组长），是中国物理学会副理事长，国家自然科学基金委员会监督委员会副主任，并担任中国科学院哲学研究所学术委员会主任、北京大学物理学科卓越人才培养指导委员会主任。

他长期从事量子物理、数学物理、量子信息基础理论的研究，其原创性的研究工作有重要国际影响。目前工作集中在复杂体系统计热力学、能源物理和可靠性理论的研究，开展了面向国家需求的科技发展战略研究和模式创新探索。目前他主持国家自然科学基金委员会的基础中心项目《基础能源物理的科学问题》。他十分重视教育和教学工作，连续讲授高等量子力学大课多年，著有《经典杨-米尔斯场理论》和《量子力学现代教程》。他10次被评为中科院“优秀导师”，指导的研究生有2人获全国“百篇优秀博士学位论文”、10余人获得“中国科学院优秀博士论文”和中国科学院院长特别奖等。他也是人教社中学物理教材的总顾问和前言的撰写者。

讲座摘要/Abstract:

报告系统地介绍我们过去二十年对统计热力学从基础到应用、从经典到量子、从平衡到非平衡的系列性研究工作。在量子力学框架下澄清了内能和传热的基本概念，通过热力学第二定律的微分几何量子可积性表述，“推导出” 正则热平衡态的统计分布，为统计力学提供了一个逻辑自洽的基础。其中温度作为一个积分因子， 伴随着热力学熵衍生出来。在这个框架下，我们还得到了偏离热平衡的非正则态，揭示了有限尺寸热力学系统和有限时间过程中信息关联的存在，如黑洞等小系统的辐射关联及其信息丢失现象。对于有限时间热循环的熵产生,得到了功率-效率约束关系， 对此我们进行了系统性的实验检验，建立了其最优调控的黎曼几何方法。

主讲人 2 /Speaker 2:

李伟 研究员

中国科学院理论物理研究所

Prof. Wei Li,

Institute of Theoretical Physics, Chinese Academy of Sciences

个人简介/Biography:

Wei Li is a Researcher at the Institute of Theoretical Physics, Chinese Academy of Sciences. His research is centered on strongly correlated many-body theory and computation, quantum magnetism, and correlated electrons. He has been dedicated to developing new tensor-network approaches and applying them to cutting-edge problems. Wei Li has published over 80 research papers in international research journals including Nature, Natue Physics, and PRL, etc. He has received support from both the NSFC Excellent Youth Program and the Chinese Academy of Sciences Hundred Talents Program. He leads the Youth Team supported by the Chinese Academy of Sciences and the Ministry of Finance for stable support in basic research, focusing on "New Approach to Sub-Kelvin Refrigeration with Quantum Materials".

讲座摘要/Abstract:

Understanding the pressure effects in bilayer nickelate superconductors poses a fascinating challenge. Using density matrix renormalization group (T=0) and thermal tensor network (T>0) methods, along with density functional theory calculations, we investigate the intriguing interplay between the two e_g orbitals that explains the pressure-dependent high-Tc superconductivity in bilayer nickelates. By exploiting a two-orbital model incorporating both Hund's rule coupling and interorbital hybridization, we identify three distinct superconductive (SC) regimes: hybridization dominant, Hund's rule dominant, and hybrid-Hund cooperative regimes. In these SC regimes, both the d_x2-y2and d_z2 orbitals exhibit algebraic pairing correlations with similar Luttinger parameters K_SC. However, the former always has much greater amplitude than the latter. This is also reflected in the pairing susceptibility results, where the d_x2-y2electron exhibits an algebraic divergenceat temperaturehigher than that of the d_z2 orbital. With realistic parameters relevant for the compound, we find the Hund's SC regime is pertinent. As hybridization V further enhances under pressure, it can lead to significant interorbital frustration, which in turn suppresses SC correlations. This mechanism explains the recent observation of a right-angled triangular SC phase in experiments [J. Li, et al., arXiv:2404.11369 (2024)]. Our findings offer a comprehensive account of the rise and fall of high-Tc superconductivity in pressurized bilayer nickelate La₃Ni₂O₇ and also La₂PrNi₂O₇.

讲座联系人/Contact:

理学院，朱老师，邮箱：zhuyi48@westlake.edu.cn

School of Science, Ms. Yi Zhu, Email: zhuyi48@westlake.edu.cn