鋰電儲能、原子調控、共振理論、相對論量子場論 | 本週物理講座

1

報告人：郭浩宇，Cornell University

時間：1月7日（週二）10:00

單位：中國科學院物理研究所

地點：M830

摘要：

Measurement-induced phase transitions (MIPTs) in monitored quantum dynamics are non-equilibrium phase transitions between quantum-chaotic (volume-law entangled) and entanglement-suppressed, area-law phases. Here we reveal how monitored dynamics are situated within the framework of general far-from-equilibrium, quantum condensed-matter physics. Measurement-induced heating effects scramble the distribution function in generic (interacting) monitored fermion systems, and this enables a simplified symmetry-based description of the dynamics. We demonstrate the equivalence of the Keldysh technique with the conventional Statistical-Mechanics Model for circuits, resulting from a doubled Hilbert-space (Choi-Jamiolkowski) mapping. We illustrate this using the monitored dynamics of interacting fermions with a conserved charge, deriving a unified effective field theory that captures all phases and phase transitions. The non-interacting counterpart in 1D space only has an area-law phase, with no MIPT. This was explained via an effective non-linear sigma model replica field theory possessing a very large symmetry. We show that other phases and phase transitions emerge when the replica symmetry is reduced by interactions. The reduced symmetry combines a replica permutation symmetry and charge-conservation within each replica. The former and its spontaneous breaking govern the MIPT, which can be recognized via a separatrix in the renormalization group flow. The replica-resolved charge conservation dictates the ``charge-sharpening" transition between two kinds of dynamics, where the global charge information is either hidden or reconstructible from the measurements. The field theory explains why the charge-sharpening transition should occur only in the volume-law phase. Our framework provides a template for other classes of MIPTs and situates these within the arena of non-equilibrium condensed matter physics.

報告人簡介：

Haoyu Guo is a Bethe postdoctoral fellow at Cornell University. He received his PhD from Harvard University under the supervision of Prof. Subir Sachdev, and his research focused on understanding non-Fermi liquids and thermal Hall effects in quantum materials. He spent his undergraduate at Peking University and MIT, where he worked with Prof. Leonid Levitov on the hydrodynamics of electron fluid. Recently, his interests expanded to understanding non-equilibrium quantum systems, with a focus on dynamical freezing in Floquet systems and measurement-induced phase transitions in monitored fermionic systems.

2

報告人：韓成成，中山大學

時間：1月7日（週二）14:00

單位：中國科學院理論物理所

地點：北樓322

摘要：

The tiny neutrino masses are most naturally explained by the seesaw mechanism through singlet right-handed neutrinos, which can further explain the matter-antimatter asymmetry in the universe. We propose a new approach to study cosmological signatures of neutrino seesaw through the interaction between inflaton and right-handed neutrinos. After inflation the inflaton predominantly decays into right-handed neutrinos and its decay rate is modulated by the fluctuations of Higgs field which act as the source of curvature perturbations. We demonstrate that this modulation produces primordial non-Gaussian signatures, which can be measured by the forthcoming large-scale structure surveys. We find that these surveys have the potential to probe a large portion of the neutrino seesaw parameter space, opening up a new window for testing the high scale seesaw mechanism.

報告人簡介：

韓成成，中山大學物理學院副教授、博士生導師。他2014年在理論物理所取得博士學位，之後分別在亞太理論物理中心(APCTP)、東京大學卡弗裡數物連攜宇宙研究機構(Kavli IPMU)、韓國高等研究院(KIAS)從事博士後研究。2020年入職中山大學任現職，併入選中山大學中青年傑出人才計劃。2023年起受聘爲亞太理論物理中心的協聯研究員(APCTP fellow)。已在PRL, JHEP等雜誌發表論文五十餘篇，總引用兩千餘次。主要研究興趣包括LHC上的新物理、粒子宇宙學、暗物質模型等。

3

報告人：Gen Ye，Leiden University

時間：1月7日（週二）14:00

單位：中國科學院理論物理所

Zoom Meeting ID: 860 1220 0416

Passcode: 342961

摘要：

The cosmic microwave background (CMB) is one of the most precise measurements ever made in cosmology. It is great success of LCDM to explain the observed CMB spectra with only six parameters. However, recent study of the cosmological tensions, especially that of early dark energy, reveals the fact that even CMB can accommodate beyond a LCDM dark component occupying up to 10% of the total energy budget during recombination when the CMB is generated. This opens up an important window of studying modified gravity before and near recombination. In this talk, I will discuss some of my recent findings about modified gravity, within the framework of scalar-tensor theories, in light of recent BAO, SNIa and CMB observations. I will show that modified gravity might play an important role in restoring concordance from the cosmological tensions.

報告人簡介：

Dr. Ye got his Bachelor’s degree in 2018 and Ph.D. in 2022 under the supervision of Prof. Yun-Song Piao at the University of Chinese Academy of Sciences, then moved to Leiden University as a postdoctoral researcher. His research interest lies on probing the fundamental laws of physics with cosmological observations, with an emphasis on gravity and the cosmological tensions. He has discovered the possible connection between the Hubble tension, the anti-de Sitter vacuum and the axion of mass 10^-26 eV. He has also developed a novel way of observing early Universe physics through resonance in the gravitational wave background. His recent research uncovered evidence of modification to general relativity in the new cosmological observations, which might be the key to restoring cosmological concordance.

4

報告人：Christoph Hanhart，Forschungszentrum Jülich

時間：1月8日（週三）10:00、1月9日（週四）10:00

單位：中國科學院理論物理所

地點: 國科大中關村校區教學樓 S104

摘要：

In these lectures the concepts of S-matrix theory and their implications for a theoretically sound description of resonances are discussed. In particular I will explain the connection between causality and analyticity, the implications of unitarity for production reactions and scattering amplitudes and the concept of positivity. Finally I will explain under which conditions certain simplified descriptions are justified for individual resonances.

報告人簡介：

Christoph Hanhart is the recipient of the PIFI Distinguished Scientist Award (2025). He studied physics in Bonn and Sydney. As a theoretical physicist he works on phenomena of the strong interaction at the boundary between nuclear and particle physics at the Jülich Research Centre and at the University of Bonn, where he also holds an extraordinary professorship. The current focus is on investigations of exotic hadron states. He is a member of the Particle Data Group (PDG) and received the Teaching Award of the University of Bonn in 2018.

5

報告人：Izat Baybusinov，University of Fribourg

時間：1月8日（週三）10:30

單位：中國科學院理論物理所

地點: 北樓322

摘要：

In economic literature much emphasis is put into considering what are the most useful actions given a standard game. The game is defined by a set of utilities and the interest is to deduce what are the most useful action that an agent can take. Concepts like the Nash equilibrium arise where agents defend their own interests from the other's actions but from which no collaboration is possible. This is evident in the Prisoner dilemma game where agents’ best actions is to defect which results in a net loss for both parties.

Due to this problem we study how cooperation can arise in a game and, most importantly, how two agents can interact between themselves to reach a common agreement. This leads to the proposal of a simple two players game we call negotiation where two players can reach a common solution which has interesting properties. In this setting we observe that cooperation arises when there is information scarcity in the game which results in the people's willingness to compromise their own best choice.

6

報告人：李健寧，東北師範大學

時間：1月8日（週三）14:00

單位：中國科學院物理研究所

地點：M樓253會議室

摘要：

對於驅動-耗散量子系統來說，主方程可以描述其動力學和穩態。其中穩態是由泵浦（能量輸入）和耗散（能量損失）之間的競爭所主導的一種動態平衡。最近，非線性Kerr光學腔中動態光磁滯現象引起了人們的關注，它類似於磁性材料中的磁滯回線。本報告利用二能級原子來調控這一特性，並闡明調控背後的機制與Liouvillian間隙的行爲相關。此外，通過平均場方法給出了調控的臨界點並與數值結果進行了比較；同時分析原子的引入對光學腔帶來的影響。

報告人簡介：

李健寧博士於2020年6月獲得東北師範大學學士學位，現就讀於東北師範大學，導師爲衣學喜教授。碩博連讀期間，共發表學術論文8篇，其中第一作者5篇；兩次獲研究生國家獎學金以及優秀研究生稱號。

7

報告人：張浩然，四川師範大學

時間：1月9日（週四） 9:30

單位：中國科學院理論物理所

地點：北樓202

摘要：

Scattering amplitudes encode the essential physical information of microscopic interactions and serve as the bridge between theoretical framework and experimental data in quantum field theories (QFTs). Feynman diagrams provide a standard method for calculating scattering amplitudes, and the calculation of one-loop Feynman diagrams is usually significant or even indispensable. Passarino-Veltman Reduction (PVR) can systematically and efficiently reduce the calculation of one-loop Feynman diagrams in relativistic QFTs, and is suitable for large-scale calculations of physical processes related to one-loop Feynman diagrams. The application prerequisite of PVR is that the system respects Lorentz symmetry, which requires not only relativistic energy-momentum relations but also zero temperature and zero density. In many practical problems, physical quantities depend on finite temperature and/or finite density, and finite temperature or finite density specifies a special inertial reference frame for measuring temperature or density, thereby destroying Lorentz symmetry and making PVR no longer applicable. In this talk, I will introduce generalized PVR that can reduce one-loop Feynman diagrams in relativistic QFTs at finite temperature and/or finite density. This reduction method can be applied to the study of physical properties in hot dense quark matter/nuclear matter.

報告人簡介：

Hao-Ran Chang, is an associate professor of physics at Sichuan Normal University. He joined the Department of Physics at Sichuan Normal University after receiving his Ph.D. from the University of Science and Technology of China in 2012. He visited the Department of Physics at McGill University from 2017 to 2018. His research interests include the reduction of one-loop Feynman diagrams in finite-temperature field theory, and Higgs decays in particle physics, and collective excitations, optical conductivity, and magnetic interactions in condensed matter physics as well.

8

報告人：周昌鬆，香港浸會大學

時間：1月9日（週四） 10:00

單位：中國科學院理論物理所

地點：北樓322

摘要：

Neural criticality has emerged as a unified framework that reconciles diverse multiscale neural dynamics such as the irregular firing of individual neurons, sparse synchrony in neural populations, and the emergence of scale-free avalanches. However, the functional role of neural criticality remains ambiguous. In particular, how highly sensitive and variable critical neural dynamics coexist with reliable neural representation is an unanswered question. In this study, we investigate the neural dynamics and representations in response to external signals in excitation–inhibition (E-I) balanced networks. Our findings reveal that, in contrast with the traditional critical branching model, the critical state of the balanced network simultaneously achieves maximal response sensitivity, maximal response reliability, and optimal representation of external signals. Moreover, we unveil a functional role of neural avalanches, which are not only a hallmark of criticality but also direct contributors to neural representation. By generalizing a semi-analytical mean-field theory, we demonstrate that heterogeneity in inhibitory connections is a mechanism underlying the heterogeneity of steady-state firing rates in the neural population, enabling the presence of signal-reliable neurons in reliable avalanches. Our study addresses a longstanding challenge concerning the functional significance of neural criticality -- the intricate coexistence of reliability and variability.

報告人簡介：

周昌鬆，物理學博士，香港浸會大學物理系物理和複雜系統講座教授，現任浸會大學非線性研究中心主任，計算及理論研究所所長，生命科學影像中心主任，曾任物理系系主任（2021-24）。1992年獲南開大學物理學士，1997年獲南開大學物理博士，1997-2007年在新加坡、香港、德國等地從事訪問研究，是洪堡基金獲得者。2007年加入香港浸會大學物理系，2011年獲香港浸會大學“傑出青年研究者校長獎”，2021年獲“傑出研究表現校長獎”，及香港研究資助局“高級研究學者獎” (2023）。周昌鬆博士致力於複雜系統動力學基礎研究及其應用，特別是網絡的複雜聯結結構與體系的動態行爲的關係和相互作用。近幾年與國際國內系統和認知神經科學家合作，把這些理論進展應用到大腦的複雜聯結結構和活動以及認知功能及障礙的分析和建模等方面研究中。周昌鬆博士對生物神經網絡複雜結構、動力學及其低成本高效益如何啓發類腦智能具有濃厚的興趣。在國際交叉學術刊物PNAS，Nature Communications, Physical Review Letters，Physics Reports，National Science Review，J Neuroscience， NeuroImage，Cerebral Cortex，PLoS Computational Biology等發表論文170餘篇 (Google Scholar引用19600餘次，H-因子爲54)。任Scientific Reports 編委，PLoS One，Cognitive Neurodynamics學術編輯，及多種國際期刊常任審稿人。

9

報告人：謝佳，華中科技大學

時間：1月10日（週五）14:00

單位：中國科學院物理研究所

地點：M樓253會議室

摘要：

在全球能源結構深刻轉型的關鍵時期，《“十四五”新型儲能發展實施方案》清晰定位了新型儲能作爲構建新型電力系統的核心技術與基礎裝備的重要地位，對推動實現碳達峰、碳中和目標具有至關重要的戰略意義。其中，鋰電池儲能技術已成爲新型儲能領域的佼佼者。截至2023年，我國鋰電儲能累計投運規模已突破33.6GW，佔新型儲能市場的97.3%，預計到2035年，裝機容量將達600GW，市場規模超萬億元。與此同時，科研界與產業界正密切關注着鋰金屬電池這一前沿領域。通過將負極材料由傳統的石墨升級爲鋰金屬，並與高比容正極材料相結合，鋰金屬電池展現出超高的理論比能量，爲儲能技術的革命性突破開闢了新的路徑。然而，無論是已大規模商業化的磷酸鐵鋰電池，還是仍處於研發攻堅階段的鋰金屬電池，在面對日益增長的儲能需求與多樣化應用場景時，均面臨着壽命延長、比能量提升及安全性強化等多重技術挑戰。本報告將深入剖析鋰離子電池與鋰金屬電池的發展現狀與挑戰，詳細介紹課題組在該領域的研究進展，涵蓋關鍵材料的創新、電極結構的優化設計、器件設計與應用等多個維度，旨在爲高性能鋰電儲能技術的持續革新與發展貢獻新的思路與方案。

報告人簡介：

謝佳，華中科技大學電氣與電子工程學院教授、博導，國家傑出青年基金獲得者，國家高層次人才計劃青年項目入選者，科技部重點研發計劃和青年973項目首席科學家，英國皇家化學學會Fellow，先進電工材料與器件研究中心副主任。2002年和2008年在北京大學和斯坦福大學分別獲學士和博士學位，曾任美國陶氏化學資深研究員、合肥國軒高科研究院院長。主要從事電化學儲能研究，主持儲能電池領域重點研發計劃、青年973和聯合基金重點等多個國家級項目，以第二完成人榮獲國家科技進步二等獎，以第一完成人榮獲新疆科技進步一等獎、中國電工技術學會科技進步一等獎和首屆青年科技獎。以第一/通訊作者發表SCI論文200餘篇，獲專利授權100餘項。擔任《儲能科學與技術》編委和Interdisciplinary Materials學術編輯。

10

報告人：殳峰，The University of Sydney, Australia

時間：1月10日（週五）15:00

單位：中國科學院物理研究所

地點：M樓253會議室

摘要：

疊層衍射成像（Ptychography）是一種基於相干衍射數據的高分辨率計算成像技術，其通過掃描樣品和記錄重疊區域的衍射圖樣，結合先進的相位恢復算法，實現對樣品結構的高精度重建。該技術突破了傳統顯微鏡光學分辨率的限制，可用於揭示納米尺度材料、半導體器件和生物樣品的微觀結構。本報告將簡要介紹悉尼大學在疊層衍射成像領域的研究背景及最新科研進展。

報告人簡介：

殳峰是悉尼大學電氣與計算機工程學院副教授。他於2002年在上海交通大學獲得信息與控制工程系學士學位，並在新加坡南洋理工大學和澳大利亞墨爾本大學分別獲得電氣與電子工程碩士及博士學位。在重返學術界之前，他曾在微電子行業（例如微電子研究所IMEC、全球領先的半導體設備供應商荷蘭ASML）工作了十多年。他目前的研究興趣包括先進量測與檢測，超精密測量及運動控制及相關技術在先進材料和生命科學等領域的應用。

封面圖片來源：https://quantumchina.com/newsinfo/6610815.html

更多報告信息：

《物理》50年精選文章