宏觀量子疊加、超快太赫茲、大氣模式 、輕子生成機(jī)制 | 本周物理講座

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報(bào)告人： 孫昌璞，中國(guó)工程物理研究院研究生院

時(shí)間：10月21日（周二）15:00

單位：中國(guó)科學(xué)院理論物理研究所

地點(diǎn)：南樓6620

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報(bào)告人：Zhenghao Zhong，SIMIS

時(shí)間：10月21日（周二）10:30

單位：北京大學(xué)物理學(xué)院

地點(diǎn)：物理西樓B105

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報(bào)告人：Hjalte Frellesvig，Zhejiang University

時(shí)間：10月22日（周三）10:30

單位：北京大學(xué)物理學(xué)院

地點(diǎn)：物理西樓B105

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報(bào)告人： Zhe Wang，Department of Physics, TU Dortmund University

時(shí)間：10月22日（周三）15:00

單位：中國(guó)科學(xué)院物理研究所

地點(diǎn)：M樓253會(huì)議室

摘要：

In the talk I will present an overview of our recent experimental studies of nonlinear terahertz dynamics in several representative classes of solid-state materials, including Dirac semimetal, semiconductor, and strongly correlated metal. By using time-resolved ultrafast terahertz high-harmonic generation spectroscopy, we are able to reveal characteristic nonequilibrium nonlinear dynamics of Dirac/Weyl fermions, may-body excitonic states and quantum critical metal at the terahertz frequencies. I will show that the ultrafast terahertz high-harmonic generation spectroscopy is very powerful for the investigation of the complex dynamic behaviors of Dirac/Weyl fermions, many-body excitons, or strongly correlated electrons, and present our understanding of the physics responsible for the very intriguing nonlinear phenomena.

報(bào)告人簡(jiǎn)介：

Professor Zhe Wang studied physics in Nanjing University, and obtained his master and PhD degrees from the University of Augsburg in Germany. Before he joined TU Dortmund University as a full professor in 2020, he was a junior group leader at the University of Cologne from 2019 to 2020 and a postdoctoral fellow in the Helmholtz-Center Dresden-Rossendorf from 2017 to 2019. His recent research focuses on terahertz dynamics of quantum materials, particularly in quantum magnets, Dirac matter and superconductors.

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報(bào)告人：李藝苑，中國(guó)科學(xué)院大氣物理研究所

時(shí)間：10月22日（周三）15:00

單位：北京大學(xué)物理學(xué)院

地點(diǎn)：物理大樓北547教室

騰訊會(huì)議：655-163-709

摘要：

無(wú)論在地球還是火星，大氣模式都是數(shù)值天氣預(yù)報(bào)與氣候預(yù)測(cè)最核心的工具之一。本報(bào)告將介紹大氣模式的構(gòu)建原理與方法，重點(diǎn)闡述模式系統(tǒng)的關(guān)鍵組成，包括:數(shù)值方案、計(jì)算網(wǎng)格、坐標(biāo)系等的設(shè)計(jì)思路與主要特征。在火星部分，報(bào)告將在簡(jiǎn)要概述火星大氣基本特征的基礎(chǔ)上，以中國(guó)新一代火星大氣模式GoMars的研發(fā)為例，介紹模式構(gòu)建思路與評(píng)估方法。希望本報(bào)告能幫助模式用戶更深入理解模式行為，也期待更多對(duì)建模感興趣的同行加入模式研發(fā)。

報(bào)告人簡(jiǎn)介：

李藝苑博士畢業(yè)于中國(guó)科學(xué)院大學(xué)，地球流體力學(xué)專業(yè)，現(xiàn)任中國(guó)科學(xué)院大氣物理研究所副研究員。自幼熱愛(ài)科學(xué)，博士求學(xué)至今，一直從事大氣模式基礎(chǔ)問(wèn)題研究，特別關(guān)注新型垂直坐標(biāo)的設(shè)計(jì)。2014-2016、2018-2022年參與中國(guó)科學(xué)院大學(xué)研究生核心課程“計(jì)算地球流體力學(xué)”授課。近年來(lái)，圍繞火星大氣模式研發(fā)開(kāi)展工作，合作發(fā)展了中國(guó)新一代火星大氣模式GoMars，相關(guān)工作被選為《科學(xué)通報(bào)》（2024年第10期）和《Advances in Atmospheric Sciences》（2025年預(yù)出版）的封面文章發(fā)表。

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報(bào)告人：何楊輝，Yang-Hui He

時(shí)間：10月22日（周三）15:00

單位：北京大學(xué)物理學(xué)院

地點(diǎn)：物理西樓3層思源報(bào)告廳

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報(bào)告人： 楊帆，北京理工大學(xué)

時(shí)間：10月23日（周四）10:00

單位：中國(guó)科學(xué)院理論物理研究所

地點(diǎn)：南樓6620

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報(bào)告人：熊汗青，北京大學(xué)

時(shí)間：10月23日（周四）14:00

單位：中國(guó)科學(xué)院物理研究所

地點(diǎn)：M樓253會(huì)議室

摘要：

Stimulated Raman scattering (SRS) has emerged as a powerful quantitative contrast mechanism for chemical imaging in recent years. Conventional SRS techniques, which operate in the frequency domain, face a fundamental trade-off between excitation efficiency and spectral resolution: while the nonlinear process benefits from ultrafast pulsed excitations, the time-energy uncertainty principle intrinsically limits spectral resolution. Additionally, spectral range and acquisition speed are mutually constrained. In this talk, I will present a novel time-domain excitation strategy developed in our lab that circumvents these limitations. By encoding Raman free-induction decays into time-domain stimulated Raman loss (SRL) signals through vibrational wave packet interference, we reconstruct the Raman spectrum via Fourier transform of the time-domain SRL signal. This approach achieves natural-linewidth-limit spectral line shapes, a spectral range determined by the laser bandwidth, and enhanced sensitivity. I will discuss our progress in obtaining self-calibrated standard Raman spectra and high-speed super-broadband Raman imaging, along with the advantages and limitations of this method for biomedical imaging applications.

報(bào)告人簡(jiǎn)介：

Prof. Hanqing Xiong is now an assistant professor of the National Biomedical Imaging Center at Peking University (selected for the National Youth Talent Program of China). He received his Bachelor's degree from the Department of Biomedical Engineering at Huazhong University of Science and Technology in 2012, followed by his Master's training at the Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology in 2015. He then pursued his doctoral studies at Columbia University, where he trained as a spectroscopic physicist and earned his Ph.D. from the Department of Chemistry in 2020. He joined Peking University as a PI in Mar. 2021. His research focuses on ultrafast molecular vibrational spectroscopy and its applications in biomedical detection and imaging. He has published systematic research innovations in the fields of (i) coherent Raman spectroscopy & imaging and (ii) mesoscale connectomics, and holds or has applied for several related invention patents.3.

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報(bào)告人：萬(wàn)義頓，復(fù)旦大學(xué)物理系

時(shí)間：10月24日（周五）9:30

單位：中國(guó)科學(xué)院物理研究所

地點(diǎn)：M樓837

摘要：

In this talk, we shall introduce a CFT factory -- a novel algorithm of methodically generating 2D lattice models that would flow to conformal field theories (CFTs) in the infrared. We realise these models by engineering the boundary conditions of 3D topological orders (SymTOs) described by string-net models. The critical points are induced by a commensurate condensation of non-commuting anyons. Our structured method generates an infinite family of critical lattice models, including the A-series minimal models, and uncovers previously unknown critical points. Notably, we discover at least three novel CFTs (with central charge c around 1.3, 1.8, and 2.5) that preserves the Haagerup symmetries, in addition to recovering previously reported examples. The non-invertible symmetries preserved at these points are dictated by a novel "refined condensation tree". The condensation trees predict large swathes of phase boundaries and sieves out second order phase transitions. This predictive power is illustrated not only in well-studied examples, such as the 8-vertex model associated with the A5 category, but also in new cases involving Haagerup symmetries, validated by an improved symmetry-preserving tensor-network renormalization group method. The critical couplings are precisely encoded in algebraic data (the Frobenius algebras and quantum dimensions of unitary fusion categories), thereby establishing a powerful and systematic route to the discovery and potential classification of new CFTs.

報(bào)告人簡(jiǎn)介：

Yidun Wan is a tenured professor of physics at Fudan University. He has a diverse educational background, with bachelor degrees in computer science and economics from South China University of Technology (1998), master of computer science from University of Pennsylvania (2002), master of physics from University of Ottawa (2004), and PhD in theoretical physics from University of Waterloo and Perimeter Institute for Theoretical Physics (2009). He also did postdoctoral research at Kinki University, Tokyo University, and Perimeter Institute for Theoretical Physics from 2009 to 2016. He joined Fudan as a professor in 2016. His research interests include cosmology, topological orders, quantum information and computation, and their interdisciplinary studies.

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報(bào)告人：趙振華，遼寧師范大學(xué)

時(shí)間：10月24日（周五）10:30

單位：中國(guó)科學(xué)院理論物理研究所

地點(diǎn)：南樓6520

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