可积量子系统、强耦合电-声系统 、引力波与中微子质量 | 本周物理讲座

1

报告人：郭领阵，天津大学

时间：6月18日（周二）11:00

单位：中国科学院理论物理研究所

地点：南楼6620

摘要：

Bosonic codes use nonclassical bosonic states to encode and process quantum information, which renders them hardware-efficient compared to codes with two-level systems. However,  it is still a challenging task to prepare high-quality bosonic code states with high efficiency. In our recent work [Phys. Rev. Lett. 132 , 023602 (2024)], we developed a noncommutative Fourier transformation technique and the new method to generate arbitrary Hamiltonian in the Floquet phase space of a periodically driven oscillator. We establish the relationship between an arbitrary target Floquet Hamiltonian in phase space and the periodic driving potential in real space. Our protocol can be realized in a range of experimental platforms for nonclassical state generation and bosonic quantum computation.

报告人简介：

Dr. Lingzhen Guo is currently an Associate Professor at the Center for Joint Quantum Studies, Tianjin University. He finished his undergraduate and graduate studies at the Beijing Normal University. From 2010.09 to 2012.08, he worked as a joint PhD student at the Karlsruhe Institute of Technology (KIT), Germany. From 2013.08 to 2023.12, he worked as postdoc at KIT, Chalmers University of Technology (Sweden) and Max Planck Institute for the Science of Light (MPL) in Erlangen (Germany). He joined Tianjin University as an Associate Professor from April of 2023.

2

报告人：马儒军，南开大学

时间：6月18日（周二）16:00

单位：中国科学院物理研究所

地点：M253会议室

摘要：

低能耗热管理技术既是未来高新技术发展的重要保障又符合我国“双碳”的战略目标。然而，传统的热管理系统通常耗电量大、不环保、体积大等。这里，为了降低能耗，我们开展了节能高效固态热管理系统研究，从低能耗的电卡效应到零能耗的辐射效应的热管理系统，再到自持续的可穿戴固态热管理系统。利用电卡效应制备的低能耗热管理系统，不仅具备环保、高效、小型化且结构简单，还可以对电子器件进行时空精准控温。利用辐射效应制备的零能耗热管理系统，不仅解决了传统辐射热管理系统在应对动态温度变化时的局限性，更实现了保温与制冷双模式的零能耗切换效果，显著提升了热管理系统的能效和灵活性。另外，通过光伏模块与电卡-静电力模块集成的自持续全天候可穿戴热管理衣物，从根本上解决了电卡效应热管理系统的供能难题，可根据人体制冷/加热需求实现了快速体温调节，并扩大了人体热舒适区范围。这种节能的固态热管理系统为我国“双碳”目标的顺利实现提供了理论和技术支撑。

报告人简介：

马儒军，南开大学材料科学与工程学院教授、博导，国家四青人才，科技部国家重点研发计划“变革性技术”重点专项课题负责人，主持国家自然科学基金面上项目（2）与国际交流项目、天津市自然科学基金重点项目等。2013年2月博士毕业于韩国成均馆大学纳米科技学院（导师：Seunghyun Baik教授），随后在该校能源科学学院与基础科学研究院从事博士后研究员的工作，并于2015年4月加入美国加州大学洛杉矶分校（UCLA）裴启兵教授课题组继续从事博士后研究员的工作。2018年9月加入南开大学材料科学与工程学院。

主要研究方向为柔性主动/被动固态制冷材料与器件及多功能柔性热电材料与器件。近年来以通讯或第一作者发表的国际著名期刊有Science (2), PNAS, Nature Communications, Joule (2), Chemical Society Reviews, Energy & Environmental Science, Advanced Materials (4), Advanced Energy Materials (2), Nano Letters (7), ACS nano (2)等；授权美国、中国、韩国专利10余项，申请国际专利2项。

3

报告人：Peiran Li，University of Minnesota

时间：6月19日（周三）10:00

单位：北京大学物理学院

地点：物理学院西B105

摘要：

Electroweak physics has been tested and exploitedat current LHC very comprehensively. It seems to be in an auto-piloting mode that our job becomes either searching BSM physics or improving the precision of SM measurement. Our recent work proposes a new channel, W boson 4-lepton decay, which people have not paid enough attention, but the current LHC is able to measure. Furthermore, this channel can be used to constrain other BSM model, such as L_\mu-L_\tau. In the latter half of my talk, I would like to switch to the SM precision measurement at future 10 TeV muon collider. Especially, I will discuss the Higgs total width measurement via vector bosonfusion at muon collider and the global constraints on Higgs effective couplings, showing the sensitivity of future muon collider.

报告人简介：

Peiran Li is currently a graduate student at University of Minnesota starting in 2021. He obtained his bachelor's degreeat Stony Brook University in 2019 and worked as research assistant at IHEP during 2020. He mainly works on particle physics, SM/BSM phenomenology, collider physics.

4

报告人：Tong (Arthur) Wu，University of Pittsburgh

时间：6月19日（周三）11:00

单位：北京大学物理学院

地点：物理学院西B105

摘要：

In this talk I will first introduce how to calculate the effective potential and gravitation wave from phase transition, the traditional method and the dimensional reduction method wil be discussed and compared. Then l will present the gravitational wave signal generated from neutrino inverse seesaw model and show the complementarity to the collider search for heavy neutral lepton.

报告人简介：

Tong (Arthur) Wu is a graduate student at the University of Pittsburgh starting in 2022, after obtained his bachelor's degree at University of Science and Technology of China.

5

报告人：Dr. Zechuan Zheng，PI

时间：6月19日（周三）15:00

单位：北京大学物理学院

地点：物理学院西B105

摘要：

This presentation focuses on the lattice and matrix bootstrap methods, distinguished by their utilization of the equation of motion as bootstrap constraints. These methods share key characteristics with the closely related fields of quantum mechanics bootstrap and many-body bootstrap. The presentation will cover the application of the bootstrap method to the matrix model theory, with a particular emphasis on the ground state of BFSS. Additionally, l will discuss the latest results in bootstrap finite N matrix model theory, including the recent bootstrap result of SU(2) lattice gauge theory.

报告人简介：

Dr. Zechuan Zheng is presently serving as a postdoctoral fellow at the Perimeter Institute of Theoretical Physics. He obtained his Bachelor's degree from Peking University in 2016 and completed his Ph.D. in theoretical physics at École Normale Supérieure, Paris, France,in 2023. His areas of research encompass applying the bootstrap method to different areas of theoretical physics.

6

报告人：Dr. Zhaoyu Han，Harvard University

时间：6月20日（周四）10:00

单位：中国科学院物理研究所

腾讯会议ID：838-194-182

会议密码：0620

摘要：

Resonating valence bond (RVB) states describe one of the most extreme classes of quantum phases that feature emergent gauge fields at low energy. Since this concept was revived by Anderson in 1973 in the spin physics context, the pursuits of such phases have been mostly restricted to frustrated antiferromagnets. In this talk, I will introduce an entirely different route to the possible realization of such phases, which builds on phonon degrees of freedom on lattice bonds – roughly realizing the original intuitive depiction of RVB by Pauling in 1949. I will provide (at least) two explicit minimal models as caricatures of certain types of electron-phonon couplings, where it can be shown with asymptotically exact arguments that deconfined gauge fields emerge in certain strong coupling regimes of their phase diagrams. Particularly I will show that such phases can appear in electronically trivial 'band insulators' proximate to ferroelectric ordering.

报告人简介：

Zhaoyu Han is a postdoctoral fellow in condensed matter theory at Harvard University. He earned his PhD from Stanford University in 2024 and BS from Peking University in 2018. His current research interests span strongly coupled electron-phonon systems, topological phases and transitions, and flat band materials.

7

报告人：Andreas Klümper，Wuppertal University

时间：6月20日（周四）10:00

单位：中国科学院物理研究所

报告地点：M830

摘要：

This talk explores the intriguing physical properties of integrable low-dimensional models, specifically focusing on 1D quantum systems and 2D classical systems such as the spin-1/2 Heisenberg chain and the 1D Hubbard model. The classical six-vertex model on the square lattice and its generalizations also play a crucial role in understanding these prototypes.

The first part of the talk elucidates the connection between 2D classical models and 1D quantum systems. By exploring the Yang-Baxter equation for local Boltzmann weights, we unveil a family of commuting transfer matrices. These matrices operate in the Hilbert space of the 1D quantum system, ultimately leading to a lattice path integral formulation of the Heisenberg and Hubbard Hamiltonians at arbitrary temperatures. The practical implications include a compact representation of thermodynamic quantities based on a finite set of non-linear integral equations, a departure from the traditional TBA approach involving infinitely many equations.

Transitioning to the second part, we delve into seminal results in integrable systems and touch upon current research topics, such as thermal and spin transport in the Heisenberg chain. A special focus is placed on the staggered Heisenberg spin chain, where we present results on the finite-size spectrum for varying sizes, ranging from $L = 10$ to $L = 10^{24}$.

8

报告人：David Wu，Harvard University

时间：6月20日（周四）15:00

单位：北京大学物理学院

地点：物理学院西B105

摘要：

Quantum gravity has a natural cutoff given by the Planck scale. However, the EFT of quantum gravity can break down at a lower scale known as the species scale, which is when higher-curvature corrections become important. Additionally, there is a third scale which marks the inverse length (or the temperature) of the smallest black hole where the EFT gives a correct description of its entropy and free energy. Understanding the distinction and interplay among these three scales can shed light on fundamental aspects of quantum gravity and have important applications to phenomenology. In this talk, l will introduce the species scale as a moduli-dependent quantity in supersymmetric theories and motivate the existence of the black hole scale in quantum gravity. At last, I will provide evidence for two global bounds of the species scale and the black hole scale over the moduli space of quantum gravity.

报告人简介：

David Wu completed his undergraduate studies at Caltech and is currently a third year PhD student in the Center of Fundamental Laws in the department of physics at Harvard University under the supervision of Prof, Cumrun Vafa. He is mostly interested in the swampland program of quantum gravity.

9

报告人：Gwenael Giacinti，贾鸿宇，上海交通大学

时间：6月20日（周四）15:30

单位：北京大学物理学院

地点：KIAA-Auditorium

摘要：

AGN jets are some of the few astrophysical environments able to confine ultra-high-energy cosmic rays, but whether they are capable of accelerating these particles is unknown. In this work, we revisit particle acceleration at relativistic magnetized shocks beyond the local uniform field approximation, by considering the global transverse structure of the jet. Using large two-dimensional particle-in-cell simulations of a relativistic electron-ion plasma jet, we show that the termination shock forming at the interface with the ambient medium accelerates particles up to the confinement limit. The radial structure of the jet magnetic field leads to a relativistic velocity shear that excites a von Kármán vortex street in the downstream medium trailing behind an over-pressured bubble filled with cosmic rays. Particles are efficiently accelerated at each crossing of the shear flow boundary layers. These findings support the idea that extragalactic plasma jets may be capable of producing ultra-high-energy cosmic rays. This extreme particle acceleration mechanism may also apply to microquasar jets.

报告人简介：

Gwenael Giacinti is a T. D. Lee Fellow at the Tsung-Dao Lee Institute, and a Tenure-track Associate Professor at Shanghai Jiao Tong University. Prior to that, he held postdoctoral researcher positions at the University of Oxford (United Kingdom) and at the Max Planck Institute for Nuclear Physics in Heidelberg (Germany), and earned his Ph.D. degree from Paris 7 University (France). He is interested in a number of topics in theoretical high-energy astrophysics and particle astrophysics, including cosmic-ray propagation, particle acceleration in pulsar wind nebulae, supernovae and supernova remnants, as well as gamma-ray astronomy. He is also interested in related plasma astrophysics problems, such as shock physics in the context of supernova shock breakout. He is the science working group coordinator of the Southern Wide field-of-view Gamma-ray Observatory (SWGO), and a member of the LHAASO Collaboration.

图片来源于：https://neutrino-science.com/a-new-gravitational-wave-collection-contains-black-holes-of-all-shapes-and-sizes/

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