1

報告人：Albert Escrivà，Nagoya University

時間：6月3日（周二）10:30

單位：中國科學院理論物理研究所

地點：北樓322

摘要：

Simulations of primordial black hole (PBH) formation are crucial for understanding the initial conditions that lead to black hole formation and for studying their properties and cosmological impact. Recently, a class of curvature perturbations known as type-II fluctuations, characterised by a non-monotonic areal radius, has attracted growing interest. However, when simulating PBH formation from type-II fluctuations using the standard Misner-Sharp approach, the evolution equations contain divergent terms (of the form 0/0), which hinder numerical progress and make the simulation impossible. In this talk, I will present a new methodology with the Misner-Sharp formalism that enables simulations of PBH formation from generic curvature fluctuations while avoiding the divergences associated with type-II curvature profiles. With the new method, we systematically study the black hole formation threshold across various fluctuation profiles and find that, for sufficiently large curvatures in the linear component of the compaction function shape around its peak, the threshold generally lies deep within the type-II regime. Furthermore, I will present an analytical formula that estimates the threshold in these cases.

報告人簡介：

Albert Escrivà received his Ph.D. from the University of Barcelona and is currently an Assistant Professor at Nagoya University. His research focuses on Primordial Black Holes, particularly their formation through relativistic numerical simulations. Previously, he held postdoctoral positions at the National Astronomical Observatory of Japan (NAOJ) in Tokyo, was a JSPS Fellow at Nagoya University, and conducted postdoctoral research at the Université Libre de Bruxelles.

2

報告人：Alessandro Bombardi，Diamond Light Source

時間：6月4日（周三）14:00

單位：中國科學院物理研究所

地點：M樓249會議室

摘要：

Synchrotron light enables precise generation, control, and analysis of photon polarization across a wide energy range. This capability selectively enhances elements of the light-matter cross-section, benefiting diverse synchrotron techniques probing materials at various scales. While dominant X-ray diffraction terms preserve photon polarization, resonant conditions or advanced scattering models reveal systematic polarization modification of diffracted photons. Analyzing this final polarization distinguishes scattering processes and accesses distinct system properties. Consequently, X-ray polarization analysis investigates magnetic/chiral order, and, combined with synchrotron spatial resolution, maps domains. This approach extends to excitations involving energy/momentum transfer. Similarly, polarized-light-excited photoelectrons probe nanoscale topological magnetic textures and domains in quantum materials, complementing diffraction resolution. In this talk, I will introduce polarized light for investigating chirality and non-collinear magnetic order, discussing its key opportunities.

報告人簡介：

Alessandro Bombardi is the principal beamline scientist at the I16 Material and magnetism at Diamond, the first operational beamline at Diamond that he contributed to build. Prior to this position, Alessandro was Senior Beamline Scientist, Diamond Research Fellow and visiting lecturer at Oxford University. Alessandro started his scientific career with a PhD on actinides with Prof. Gerry Lander, and since he developed a fascination for strongly correlated electron systems, quantum, and multifunctional materials that he investigates mainly using x-ray and neutron-based techniques.

3

報告人：Shigeyuki Komura，國科溫州研究院

時間：6月3日（周二）16:00

單位：中國科學院理論物理研究所

地點：北樓202

4

報告人：Wang YAO，University of Hong Kong

時間：6月4日（周三）15:00

單位：北京大學物理學院

地點：西563會議室

摘要：

In this talk, I will discuss fractional quantum anomalous Hall effects in two occasions that are rather unconventional, hosted by lattice models that are variants of the three - orbital tight - binding model for twisted MoTe?. The first is a singular flat band, with a protected touching point with a dispersive one. Such flat band can have some characters of a nearly ideal flat Chern band, except for the absence of a gap, which raises the question of whether fractional QAH states can be compatible with this band touching. I will show numerical evidences of FQAH states from both exact diagonalization and DMRG calculations. An interesting observation is the fractional QAH states exist in the limit of weak interaction strength, where the singular band touching feature is retained, but get quenched when larger interaction gaps the touching point and turn the singular flat band into a flat Chern band. The second occasion is in the opposite limit: an isolated flat band of zero Chern number, gapped from the rest bands that also have zero Chern number. And we will focus on the isolated band limit, namely interaction is always weaker than the gap, so that renormalisation by interaction leaves the flat quantum geometry and trivial topology unchanged. Starting with the Hartree - Fock band of zero Chern number, our ED calculations show unambiguous evidences of fractional QAH effect at its 2/3 filling. The ground state degeneracy rules out the relevance of band folding fractional crystal, and we do not expect there can be folded miniband to effectively display nontrivial band topology either. This example suggests that single particle topology is not the prerequisite for fractional quantum Hall state.

報告人簡介：

Wang YAO obtained his BSc from Peking University in 2001, and PhD in physics from University of California, San Diego in 2006. He joined the University of Hong Kong in 2008, and rose through the academic ranks to Chair Professor of Physics in 2019. His group works in an interdisciplinary area across condensed matter physics, quantum physics, and optical physics, with current research interest in 2D quantum materials and their twisted structures. He is a New Cornerstone Investigator, and Fellow of American Physical Society and Fellow of Optica.

5

報告人：張俊杰，山東大學晶體材料全國重點實驗室

時間：6月5日（周四）10:00

單位：清華大學物理系

地點： 物理樓W105

摘要：

高溫超導機理和新型高溫超導材料的探索一直是凝聚態物理領域的前沿研究課題。2023年中山大學王猛教授和清華大學張廣銘教授領導的研究團隊在雙層鎳氧化合物La3Ni2O7單晶中發現了臨界轉變溫度78K@18.9 GPa的高溫超導電性，引發了鎳基高溫超導研究熱潮。經過1年多的研究，仍然存在一些關鍵基礎科學問題亟待解決，包括超導轉變溫度能否提高，是否能在常壓下實現鎳基體塊高溫超導等。本報告中，我將介紹我們團隊在鎳基氧化物單晶生長、結構和物性研究方面取得的一些進展，主要包括：（1）開發鎳基高溫超導體單晶生長新方法，首次在常壓下采用助熔劑法生長了La4Ni3O10-δ和La3Ni2O7-δ單晶，克服了高壓制備條件，極大地降低了鎳基超導研究單晶制備門檻，并在高壓下觀測到超導電性；（2）設計和發現了一類全新的、長程有序排列的雜化Ruddlesden-Popper層狀鎳氧化合物，在常壓下生長了單層和雙層雜化的RP相單晶，為探索新的鎳基超導體提供了新的材料體系；（3）在常壓下生長了高質量的雙層鎳氧化合物La2SmNi2O7單晶，其超導轉變溫度為92 K，零電阻溫度73 K。發現高壓下的最高超導轉變溫度與常壓下的面內畸變正相關，指明了繼續提升鎳基超導Tc的方向。

報告人簡介：

張俊杰，山東大學教授、博士生導師。2008年本科畢業于山東大學材料科學與工程學院，并保研晶體材料研究所，師從陶緒堂教授，碩博連讀，于2013年獲山東大學材料學博士學位。2013-2017年和2017-2019年先后在美國阿崗國家實驗室John F. Mitchell課題組和橡樹嶺國家實驗室Raphael P. Hermann課題組從事博士后研究。2019年11月入職山東大學。長期從事關聯量子材料單晶生長、結構與物性研究工作，在Nat. Phys., Phys. Rev. Lett., PNAS, JACS等期刊上發表學術論文60余篇，引用2500余次，h因子26（Google Scholar）。2013年作為中國優秀博士研究生代表參加第63屆林島諾貝爾獎獲得者大會，與34位諾貝爾獎得主面對面交流；2014年獲山東省優秀博士學位論文；2016年獲教育部自然科學二等獎（第四完成人）；2017年獲美國物理學會DMP Post Doctoral Travel Awards。

6

報告人：Jaume Garriga，University of Barcelona

時間：6月5日（周四）10:30

單位：中國科學院理論物理研究所

地點：北樓322

摘要：
We discuss several inflationary mechanisms for seeding the formation of primordial black holes (PBH), which lead to a diversity of initial mass functions. Some scenarios are based on inflationary relics, such as high energy vacuum bubble remnants, while others are based on the collapse of standard adiabatic perturbations. We point out that the two mechanisms may often coexist. We also report on recent progress in determining the PBH mass function in a universe filled with nearly Gaussian adiabatic perturbations with an extended power spectrum. Our results may significantly impact overproduction bounds on the amplitude of the power spectrum, and tighten the viable mass range for primordial black holes as dark matter.

報告人簡介：

Jaume Garriga is a Professor of Theoretical Physics at the University of Barcelona since 2021, following his tenure as associate professor at UAB/IFAE since 1994. He is a specialist in general relativity, quantum field theory in curved space, and inflation, with pioneering contributions to the theory of cosmological perturbations, brane world gravity and cosmology, and vacuum transitions in the multiverse. He received the Young investigator Distinction from the Generalitat de Catalunya in 2002. He is a founding member of the Gravitation, Strings and Cosmology consolidated group at the Institute of Cosmos Sciences of the University of Barcelona, ICCUB.

7

報告人：朱華星，北京大學

時間：6月5日（周四）15:00

單位：中國科學院理論物理所

地點：北樓CCAST五樓報告廳

8

報告人：殷嘉鑫，南方科技大學

時間：6月5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：

本次報告將介紹籠目晶體材料的研究進展，著重討論我們觀測到的陳數拓撲磁體、手性電荷序和磁性超導電性等一系列兼具拓撲與關聯的量子物態。這些觀測開啟了拓撲籠目磁體與超導體的探索之路，揭示了阻挫材料中電磁耦合與量子調控的基本規律，為下一代量子器件發展提供了新思路。

報告人簡介：

殷嘉鑫本科畢業于中國科學技術大學，在物理研究所取得博士學位，后在美國普林斯頓大學任博士后與研究員。2022年他加入南方科技大學物理系，任副教授。他研究方向為利用先進能譜手段發現、理解和調控固體材料中的電子結構。他已發表多篇論文，含11篇Nature/Science, 14篇Nature Physics/Nature Materials/Nature Reviews，36篇PRL/NC等。

9

報告人：Jianghui Ji，中國科學院紫金山天文臺

時間：6月5日（周四）15:30

單位：北京大學物理學院

地點：KIAA-auditorium

摘要：

The detection and study of potentially habitable exoplanets is a cutting-edge topic in contemporary astronomy. The National Medium- and Long-Term Development Plan for Space Science (2024–2050) has been officially released, identifying “Nearby Habitable Exoplanets” as one of its key scientific frontiers.The Closeby Habitable Exoplanet Survey (CHES) (http://www.ps.pmo.cas.cn/CHES/)) aims to search for Earth-like planets in the habitable zones around 100 nearby Sun-like stars located within approximately 32 light-years of the Solar System. Utilizing micro-arcsecond-level space-based astrometry, CHES will conduct a comprehensive census of nearby planetary systems, determining the true masses and three-dimensional orbital parameters of detected planets, and establishing a complete database of nearby exoplanets.

The CHES telescope features a 1.2-meter aperture and will operate at the Sun-Earth Lagrangepoint L2 for a planned five-year scientific mission. The mission is expected to achieve significant breakthroughs in detecting terrestrial planets within the habitable zones of nearby solar-type stars. With its innovative technological approach, CHES offers unique advantages in the search for potentially habitable Earth-like planets.This pioneering research will address fundamental questions such as:What is the distribution of nearby habitable exoplanets?Is Earth unique?andHow do planets become cradles of life?

報告人簡介：

Dr. Jianghui JI is a Research Professor and Director of the Laboratory at Purple Mountain Observatory, Chinese Academy of Sciences (CAS). He serves as Chair of the Planetary Science Division of the Chinese Astronomical Society and Director of the CAS Key Laboratory of Planetary Sciences. He is also a recipient of the National High-level Talent Program. His research focuses on exoplanets, protoplanetary disks, and small bodies in the Solar System. He has authored over 200 scientific publications. He has led several major research projects, including a Key Program of the National Natural Science Foundation of China and the CAS Strategic Priority Program on Space Science. His work has been recognized as part of China's Top Ten Astronomical Advances of the Year on three occasions and has earned him the Jiangsu Provincial Science and Technology Award. He has also been frequently invited to deliver plenary and keynote talks at international conferences.

10

報告人：徐英軒，柏林洪堡大學

時間：6月9日（下周一）14:00

單位：中國科學院理論物理所

地點：北樓202

摘要：

The computation of scattering amplitudes connects formal theory, phenomenology, and experiment. Feynman integrals, as the most established method for evaluating scattering amplitudes, encounter growing computational challenges as experimental precision increases. Integration-by-parts (IBP) reduction, though widely used, often becomes the main bottleneck in the evaluation process. Our package, NeatIBP1.1 + Kira, uses syzygy and module intersection techniques to generate compact IBP systems and performs automatic reduction using Kira, significantly improving reduction efficiency. The latest version also incorporates the spanning cuts method, further reducing the overall computational complexity for particularly demanding problems.

報告人簡介：

Dr. Yingxuan Xu is currently a postdoctoral researcher at Humboldt University of Berlin, where he also earned his PhD in Physics in 2025. His research focuses on the computation of scattering amplitudes in high-energy and gravitational physics, including QCD Feynman integrals, amplitude calculations in gravitational wave processes, and the development of novel computational techniques.

封面圖片來源：https://www.sohu.com/a/230428361_465915

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