1

報告人：Li Yan，Fudan University

時間：4月22日（周二）10:30

單位：北京大學物理學院

地點：物理學院西樓B105

摘要：

There must be electromagnetic fields created during high-energy heavy-ion collisions. However, as the quark-gluon plasma (QGP) starts to evolve hydrodynamically (around 1fm/c), these fields become very likely weak comparing to the energy scales of the strong interaction. In this talk, I will introduce the weak magnetic effect in the standard hydrodynamic formulation, which emerges in QGP close to local thermal equilibrium as the dissipative correction to the quark phase space distribution function. Although it is a small correction, we found that the weak magnetic field can be crucial to the anisotropic emission of direct photons (the direct photon puzzle), the polarization of thermal dilepton from QGP, and the sign change of local Lambda hyperon polarization.

報告人簡介：

Li Yan is currently an Assistant Professor at the Institute of Modern Physics, Fudan University. He obtained his PhD in 2013 from Stony Brook University. Afterward, he joined the Institut de Physique Théorique (IPhT) at Saclay, France, in 2013, and later the Department of Physics at McGill University in 2016 as a postdoctoral researcher. His research focuses on relativistic hydrodynamics and its application to quark-gluon plasma in high-energy heavy-ion collisions, the electromagnetic properties of quark-gluon plasma, and non-equilibrium systems.

2

報告人：孫志遠，清華大學

時間：4月22日（周二）12:00

單位：江蘇省物理學會

鏈接：

摘要：

The ponderomotive force is an effective static force that a particle feels in an oscillating field. We generalize this notion to the static force felt by the collective degrees of freedom in periodically driven quantum many-body systems, and propose it as a tool to engineer their non-equilibrium steady states beyond the single particle level. Applied to materials driven by light, the ponderomotive potential is intimately related to the equilibrium optical conductivity, which is enhanced close to resonances. We show that the ponderomotive force from the uniform incident light may be used to induce exciton condensates in semiconductors, to generate attractive interactions leading to superconductivity in certain electron-phonon systems, and to create additional free energy minima in systems with charge/spin/excitonic orders. We also show that the ponderomotive force is a universal tool to tune electronic phases in optically driven cavities. These effects are presented with experimentally relevant parameters.

報告人簡介：

Zhiyuan Sun obtained his BS in 2012 from University of Science and Technology of China, and his PhD in 2018 from UC San Diego. He worked as a postdoctoral/associate research scientist at Columbia University during 2018~2021, and as an HQI postdoc Fellow at Harvard University during 2021~2022. Since 2022, he has been an assistant professor at the physics department of Tsinghua University. Zhiyuan works on condensed matter theory, specifically, nonequilibrium phenomena in many-body systems, light-matter interactions, and nano-optics.

3

報告人：李峣，南開大學

時間：4月23日（周三）10:00

單位：中國科學院理論物理研究所

地點：北樓5層CCAST報告廳

摘要：

Topological defects are fundamental concepts in theoretical physics, widely interested by fields from cosmology to condensed matter. To tile the surface by triangular lattice cells alone, topological defects become inevitable due to geometric frustration. The theory is well developed by Casper-Klug inspired by viruses. However, to tile the spherical surface by both types of lattice cells, the answer is wide open. We have discovered surprising novel types of topological defects, including enclave d and counter - enclaved domain defects, which possess unexpected topological intensities. We will also discuss the new global symmetries arising from the newly found topological defects. Our study unlocks new avenues for understanding numerous challenges in physics, materialscience, and related biological physics.

報告人簡介：

李峣，2014年于清華大學物理系獲得理論物理博士學位，期間2013-2014年在加拿大滑鐵盧大學訪問研究。隨后在AMOLF和代爾夫特理工大學從事博士后研究工作，2021年加入南開大學物理學院任副教授。長期從事軟物質統計物理理論和模擬研究工作，研究興趣包括微分幾何下的統計物理：生物膜彈性和動力學、膠體、高分子、蛋白核酸等生物分子的組裝和動力學等。

4

報告人：Ching Hua Lee，National University of Singapore

時間：4月23日（周三）15:00

單位：北京大學物理學院

地點：西563會議室

摘要：

Non-Hermitian phenomena such as the non-Hermitian skin effect (NHSE) and exceptional point sensitivity have no Hermitian analogs, and have lately reshaped the way we understand band structures and topology. In this talk, I shall introduce some new ideas that extend the current repertoire of novel non-Hermitian phenomena. such as system-size dependent generalized Brillouin zones (GBZs), as well as GBZs defined in phase space. I shall also highlight how the NHSE can interplay with the geometric defectiveness of exceptional points to lead to novel exceptional bound bands with super volume-law negative entanglement scaling. Finally, I will also review how non-Hermitian processes havebeen recently simulated in unitary quantum simulators.

報告人簡介：

Prof Ching Hua Lee obtained a PhD from Stanford University under the tutelage of Prof Xiaoliang Qi. He joined the National University of Singapore in 2020, and is now heading a team focusing on exploring novel non-Hermitian phenomena, as well as their simulation on classical and quantum circuits. Prof Lee publishes regularly in top scientific journals, and has been cited over 10000 times in the recent years.

5

報告人：蔡子，上海交通大學

時間：4月24日（周四）15:00

單位：北京大學物理學院

地點：物理大樓中212報告廳

摘要：

Spontaneous symmetry breaking and elementary excitation are two of the pillars of condensed matter physics that are closely related to each other. The symmetry and its spontaneous breaking not only control the dynamics and spectrum of elementary excitations, but also determine their underlying structures. In this talk, we study the excitation properties of non-equilibrium quantum matters: In the first part, we propose an instanton-like excitation that represents a tunneling between two ``degenerate'' time crystal phases, which spontaneously breaks the discrete temporal translational symmetry. In the second part, we will discuss how the non-equilibrium feature of a driven-dissipative magnet qualitatively changes the dynamical behavior of the quasi-particles and give rise to an emergent confinement between them.

報告人簡介：

蔡子，2010年于中國科學院物理研究所凝聚態理論專業取得博士學位。先后在美國加州大學圣迭戈分校，德國慕尼黑大學，奧地利科學院量子光學與量子信息研究所從事博士后工作。現任上海交通大學物理與天文學院教授，博士生導師。主要從事凝聚態物理以及相關領域的數值和理論方面的工作，研究領域涉及強關聯電子系統，光晶格中的超冷原子,開放量子多體系統，非平衡統計物理，機器學習方法在物理學中的應用等方向，近年來發表括1篇Science、12篇Phys. Rev. Lett.在內的SCI論文五十余篇。

6

報告人：Mark Thompson，利茲大學

時間：4月24日（周四）15:30

主辦：北京大學物理學院

地點：KIAA-auditorium

摘要：

I will describe the SKA precursor telescope MeerKAT and some of its recent results, concentrating on the largest and deepest Galactic Plane survey carried out with MeerKAT, the SARAO MeerKAT 1.3 GHz Galactic Plane Survey (SMGPS). SMGPS is revolutionising the study of Galactic radio populations and has resulted in the discovery of many new Supernova Remnants, planetary nebular, and a novel population of non-thermal radio filaments in the Galactic Plane. I will also look forward to potential upgrades to MeerKAT and the kinds of surveys that will be possible with the Square Kilometre Array.

報告人簡介：

Mark started out his studies with a BSc in Astronomy and Astrophysics and an MSc in Electronics at the University of Newcastle-upon-Tyne (UK) from 1990-1994. After working as a software engineer he passed his PhD in Millimetre Wave Astronomy at the University of Kent (UK) in 1999 where he worked as a postdoc for the following 5 years. Mark became a lecturer at the University of Hertfordshire (UK) in 2004, eventually becoming Dean of the School of Physics Astronomy and Mathematics in 2015 and Professor Astrophysics in 2019. In 2021 Mark joined the University of Leeds (UK) as their new Head of the School of Physics and Astronomy, where he is now the Head of the Astrophysics Research Group. Mark’s main research interests are in massive star formation and Galactic Plane surveys. He works mainly in the far-infrared to radio wavelength ranges and has been closely involved in most of the major Galactic Plane surveys, e.g. with Herschel, the JCMT, JVLA and MeerKAT. His most recent survey project is the SARAO MeerKAT 1.3 GHz Galactic Plane survey, the most sensitive radio survey of the Galactic Plane yet carried out.

7

報告人：Nicolò Defenu，ETH Zurich

時間：4月24日（周四）16:00

單位：中國科大統計和計算物理鄧友金課題組

鏈接：

摘要：

This talk explores the unique non-equilibrium phenomena in quantum many-body systems with long-range interactions, driven by recent experimental advancements. We will review the equilibrium properties of long-range interacting quantum spin systems, focusing on the variable-range quantum XY model and its equilibrium phase diagram. The impact of finite-range interactions on the quantum paramagnetic and ferromagnetic phases will be examined. The core of the talk addresses out-of-equilibrium dynamics, including the spreading of quantum correlations, slowdown of entanglement dynamics, suppression of thermalization, and the appearance of long-lived metastable states. The stabilization of non-equilibrium phases by periodic driving, such as discrete time crystals, will also be discussed.

This talk aims to provide a comprehensive overview of recent advances, emphasizing the need for a unifying framework to connect few-body mean-field physics with many-body physics of quasi-local interactions, with implications for future quantum-technological applications.

報告人簡介：

Nicolò Defenu is an Italian physicist specializing in theoretical physics, particularly in quantum many-body systems and critical phenomena. He completed his BSc and MSc with honors at Sapienza University of Rome and earned his PhD from the International School for Advanced Studies (SISSA) in Trieste in 2017. After his PhD, Defenu held postdoctoral positions at the Institute for Theoretical Physics in Heidelberg and ETH Zurich. Among several grants and fellowships, he received the ERC Starting Grant on 2022 and, one year later, became an assistant professor at ETH Zurich. His research focuses universality, low-energy physics and quantum technology.

8

報告人：Anupam Chattopadhyay，南洋理工大學

時間：4月24日（周四）22:00

單位：圣母大學、麻省理工學院

鏈接：

摘要：

量子計算在算法、軟件和硬件等所有設計堆棧方面取得的重大進展，已經讓我們無法忽視量子計算對我們周圍世界的影響。我們將在本講座中介紹量子計算的兩個方面。首先是高效電路設計和自動化挑戰，以及我們如何從經典計算中借鑒一些知識。最后，我們將介紹量子計算機實驗案例研究。其次，大規模量子計算機最重要的實際威脅是公鑰密碼學。我們將通過開發和標準化后量子密碼學（PQC）基元來應對這一威脅。我們將討論各種PQC候選方案以及遷移到量子安全環境的危險。

報告人簡介：

Anupam Chattopadhyay分別于2000年、2002年和2008年獲得印度賈達夫普爾大學電子工程學士學位、RWTH Aachen理學碩士學位和RWTH Aachen博士學位。自2014年9月起，他在新加坡南洋理工大學計算機與數據科學學院擔任副教授，任期自2019年8月起。他的研究興趣包括新興技術、電子設計自動化、系統設計以及網絡安全與人工智能之間的交叉課題。Anupam 是 IEEE 和 ACM 的資深會員。他曾獲得 JSPS 訪問獎學金，并擔任過IEEE EDA理事會杰出講師。他的研究成果發表在 ACM/IEEE Transactions、Nature Scientific Reports、Physical Review、多部研究專著、Springer Major Reference Works上，并促成了 EDA、物聯網和網絡安全領域的多項衍生產品/技術轉讓。

9

報告人：蔡恬吉，SLAC National Accelerator Laboratory

時間：4月25日（周五）11:00

單位：北京大學物理學院

地點：物理學院西樓B105

摘要：

AI for fundamental physics is now a burgeoning field, with numerous efforts pushing the boundaries of experimental and theoretical physics, as well as machine learning research itself. In this talk, I will introduce a recent innovative application of Natural Language Processing to the state-of-the-art precision calculations in high energy particle physics. Specifically, we use Transformers to predict symbolic mathematical expressions that represent scattering amplitudes in planar N = 4 Super Yang - Mills theory—a quantum field theory closely related to the real - world QCD at the Large Hadron Collider. Our first results have demonstrated great promises of Transformers for amplitude calculations, while its major challenges are being addressed by ongoing work. This study opens the door for an exciting new scientific paradigm where discoveries and human insights are inspired and aided by an AI agent.

報告人簡介：

Tianji Cai (蔡恬吉) is a postdoctoral research associate in the Fundamental Physics Directorate at the SLAC National Accelerator Laboratory, and a research affiliate at the Lawrence Berkeley National Laboratory. She obtained her Ph.D. degree in 2023 at University of California, Santa Barbara, and holds two bachelor's degrees from Duke University and Shanghai Jiao Tong University. Her research interest lies at the intersection of High Energy Theory (HEP) and Artificial Intelligence (AI), with a focus on developing novel machine learning frameworks for collider phenomenology and scattering amplitudes. She’s also interested in using HEP to aid theoretical understanding of AI systems.

10

報告人：吳從軍，西湖大學

時間：4月27日（下周一）9:00

主辦方：國際納米熱力學讀書會、《概率論沉思錄》讀書會、蔻享學術、科普中國、返樸

鏈接：

摘要：

E.T.Jaynes 是著名數學物理學家，曾任華盛頓大學和斯坦福大學教授:在統計力學和概率統計推斷方面有杰出貢獻。因提出了最大原理(1957年)和 Jaynes-Cummings 模型(1963 年) 而聞名于世。Jaynes 大力提倡將概率論解釋為邏輯的延伸。《概率論沉思錄》(Jaynes,ProbabilityTheory: The Logic of Science)凝聚了他畢生的研究成果和心得,將概率論和統計推斷融合在一起，作為整個科學的邏輯基礎。該書表明，概率論的應用范圍遠比傳統頻率派所設定的要廣泛，他用新的觀點生動描述了概率論(特別是貝葉斯理論)在數學、物理學、化學、生物學和經濟學等領域中的廣泛應用,揭開了眾多悖論背后的玄機。

本次報告將詳細講解《概率論沉思錄》第9 章“重復實驗：概率與頻率”。

報告人簡介：

吳從軍教授于2005年獲得斯坦福大學Ph.D.學位 (物理學)，并從2005年至2007年期間在加州大學圣芭芭拉分校Kavli理論物理研究所從事博士后研究。他于2007年加入加州大學圣迭戈分校物理系任助理教授，2011年晉升副教授, 2017年正式晉升為正教授。他曾于2008年獲Sloan Research Fellowship和海外華人物理協會（現名全球華人物理學會）杰出青年科學家獎。2018年，他當選為美國物理學會會士（APS Fellow）。2021年起，他已全職加入西湖大學，受聘物理學講席教授。在2022年，他被選為新基石研究員。吳從軍教授的研究興趣是探索新的物質狀態及其深層次的組織原理，包括超導、量子磁性、軌道物理、拓撲物態、強關聯冷原子系統、數學物理、和量子蒙特卡洛模擬。

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