重离子加速、水界面超快动力学、QCD、量子维度约化算法 | 本周物理讲座

1

报告人：Luis A. Orozco, University of Maryland and NIST

时间：7月2日（周二）10:00

单位：清华大学物理系

地点：理科楼C302

摘要：

Francium, discovered eighty-five years ago by Margarite Perey, is the heaviest alkaline atom. It is the most unstable element of the first 103 on the periodic table, and its longest halflived isotope lasts 20 minutes. At any given time, there are only a few grams distributed throughout the earth because it is the product of the decay of uranium and thorium. In-line laser trapping and cooling with an accelerator has made it available for precision spectroscopy. With my students and collaborators, we have dedicated thirty years to its spectroscopic study because its atomic and nuclear structure makes it an ideal laboratory to study the weak interaction. I will present our proposal to better understand the weak interaction at low energy, preliminary measurements of the forbidden M1 transition between states 7S to 8S, and progress towards weak interaction studies (parity violation, time violation) at TRIUMF, the Canadian subatomic physics laboratory in Vancouver.

报告人简介：

Luis Adolfo Orozco was born in Guadalajara, Mexico in 1958. He completed his engineering studies at the Instituto Tecnológico y de Estudios Superiores de Occidente in Guadalajara, Mexico and his postgraduate studies in physics at the University of Texas at Austin, obtaining his doctorate in 1987. He held a postdoctoral position at Harvard, passing part of this one at CERN, Switzerland. He returned to the United States and worked from 1991 to 2003 as a professor in the physics department of the State University of New York at Stony Brook. From 2003 to 2020 he was professor of physics at the University of Maryland in College Park, MD, USA, where he co-directed the Physics Frontier Center of the Joint Quantum Institute com 2008 to 2019. Since 2021 he is Emeritus Professor. Throughout his career Dr. Orozco has been Guggenheim Fellow (1998), Fellow of the American Physical Society (2000) Fellow of the Optical Society of America (2003), Fellow of the Institute of Physics, UK (2005), Distinguished Traveling Lecturer of the American Physical Society (2002-2025) and corresponding member of the Academia Mexicana de Ciencias since (2005). He has an Honoris Causa Doctorate from INAOE, Mexico (2016). He has graduated 23 PhD students (3 from Mexico) and more than 60 undergraduates (35 from Mexico) have worked in his group. Together with his students and collaborators he is author of more than 100 publications. As a researcher, he is interested in quantum optics, quantum information, fundamental symmetry tests, and high precision spectroscopy. Among his most recognized studies are the trapping and spectroscopy of Francium for weak – interaction studies and the field intensity correlations in quantum optics. http://www.physics.umd.edu/rgroups/amo/orozco/index.html

2

报告人：王鹏杰，亥姆霍兹德累斯顿罗森多夫研究中心

时间：7月2日（周二）16:00

单位：中国科学院理论物理研究所

地点：南楼6620

腾讯会议：494-135-619

摘要：

In recent years, the demonstration of accelerating heavy ions from relativistic plasmas to energies, which are conducive for many applications, really stand for the maturity of Laser plasma acceleration (LPA) to be capable of accelerating nearly all kinds of particles like what traditional accelerators can do. Moreover, such heavy ion beams driven by lasers have some unique features that traditional accelerators do not have, which provide an additional tool/platform to study nuclear physics, laboratory astrophysics, high-energy-density physics and cancer therapy.

报告人简介：

Dr. Pengjie Wang is currently a postdoctoral researcher at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Germany. Before that, he was a postdoc in CNR-INO (National Institute of Optics), Italy. He received his PhD from Peking University in 2021. His research interests cover laser plasma physics, laser-driven ion acceleration, advanced target fabrication, diagnosis of ion beams and plasmas, high energy density physics (HEDP).

3

报告人：郑振亚，中国科学院上海天文台

时间：7月2日（周二）16:00

单位：中国科学技术大学 - 天文学系

链接：

摘要：

当前正在运行和建造的先进望远镜如HST、JWST、CSST等正在帮助我们逐步揭开早期宇宙的神秘面纱。它涉及宇宙中早期天体，即恒星、星系和黑洞的诞生和演化，及其所产生的电离光子重新电离整个宇宙中的中性氢环境，该过程又被称为宇宙再电离。报告将基于针对早期宇宙星系的发射线星系巡天，包括LAGER和CIDER巡天、HST窄带深场HDHα项目，以及JWST/HST等深场和紫外观测，从观测上介绍对宇宙再电离的电离历史、物理过程和此时期天体演化的相关研究。报告重点介绍：（1）基于LAGER和CIDER等巡天的红移7附近的宇宙再电离历史研究；（2）基于HST和CSST等观测的再电离过程中电离光子逃逸问题研究；（3）基于JWST和LAMOST/SDSS等巡天的再电离时期星系和原初星系团及其近邻对应体的研究。

报告人简介：

郑振亚，中科院上海天文台研究员，“早期宇宙与高红移星系”课题组长，光学天文技术研究室副主任（主持工作），中国科学院特聘研究岗位（核心）。先后在2006年和2012年获得中国科学技术大学天文学学士和天体物理学博士学位，之后在美国亚利桑那州立大学和智利天主教大学开展博士后研究工作，于2016年入职上海天文台任研究员至今。目前联合承担空间站光学巡天望远镜后端多通道成像仪MCI载荷的研制任务（担任MCI责任科学家），并主持科技部重点研发专项课题。曾主持自然科学基金优青项目和面上项目、中科院高层次人才青年项目、上海市浦江人才项目。主要研究兴趣包括遥远星系、宇宙再电离以及光学天文前沿观测技术等。

4

报告人：Prof. Tahei Tahara，Molecular Spectroscopy Laboratory，RIKEN

时间：7月3日（周三）15:00

单位：中国科学院物理研究所

地点：M楼236会议室

摘要：

Liquid interfaces provide unique environments where various important chemical/physical processes occur. Heterodyne-detected vibrational sum-frequency generation (HD-VSFG) directly measures the phase and amplitude of the 2nd-order nonlinear optical signal generated only from the interface region of a few monolayer thicknesses. Therefore, time-resolved HD-VSFG provides interface-selective time-resolved vibrational spectra interpreted as the spectral change induced by photoexcitation.

We realized that femtosecond IR-excited and UV-excited time-resolved HD-VSFG were used to observe ultrafast processes directly proceeding at the water interfaces. We recently clarified the vibrational relaxation mechanism of free OH and obtained an overall picture of the vibrational relaxation process of the OH stretch at the air/water interface. Furthermore, we successfully tracked a drastically accelerated photochemical phenol reaction at the water surface. These studies on phenol photochemistry indicated the generality of the significant difference in reaction dynamics between the interface and bulk.

报告人简介：

Tahei Tahara graduated and obtained his Ph.D. from the University of Tokyo in 1984 and 1989. After being a research associate at the University of Tokyo in 1989 and at Kanagawa Academy of Science and Technology in 1990, he joined the Institute for Molecular Science (IMS) as an associate professor and started his own research group in 1995. He moved to RIKEN as a chief scientist in 2001 and has been the director of the Molecular Spectroscopy Laboratory since then. His research interests are ultrafast spectroscopy, nonlinear spectroscopy, and single-molecule spectroscopy of complex molecular systems.

5

报告人：Andrey Sadofyev，LIP，Lisbon

时间：7月4日（周四）15:00

单位：北京大学物理学院

地点：物理学院西B105

腾讯会议: 202-874-142

摘要：

Over the last decades, the theoretical picture of how hadronic jets interact with nuclear matter has been extended to account for the medium's finite longitudinal length and expansion. However, only recently a first-principle approach has been developed that allows to couple the jet evolution to the medium flow and anisotropic structure. In this talk, l will review these developments, and discuss the features of jet quenching in evolving matter. l will consider the modifications of the single particle momentum broadening distribution and single-gluon production rate, and briefly discuss the potential phenomenological implications.

报告人简介：

Andrey is a theoretical physicist working on the many-body quantum field theory and its applications in the context of QCD matter and systems with ultrarelativistic spectrum. He received his PhD from MIT in 2017, and joined LANL as an Oppenheimer fellow the same year. He moved to University of Santiago de Compostela in 2020, and was awarded a Marie-Curie fellowship in the same year. Currently, Andrey is a junior researcher at LlP Lisbon with a position funded by the Portuguese foundation forscience and technology.

6

报告人：魏世杰，北京量子信息科学研究院

时间：7月8日（下周一）10:00

单位：MindSpore Quantum Special Interest Group

链接：

摘要：

本报告首先简要介绍量子计算的背景知识以及量子算法的历史。随后介绍量子维度约化算法（QRDR）的基本框架和共振跃迁原理。最后介绍我们展示了我们的算法与两种量子分类器（量子支持向量机和量子卷积神经网络）相结合的性能，分别用于对水下探测目标和量子多体相进行分类。使用MindSpore Quantum的模拟结果表明，应用 QRDR 后，数据减少提高了处理效率和准确性。随着量子机器学习的不断进步，我们的算法有可能应用于各种计算领域。

图片来源于：https://physicalsciences.lbl.gov/2023/06/27/jet-substructure-as-a-powerful-probe-of-quantum-chromodynamics-2/

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