The Physics Colloquium has been arranged regularly since the fall semester of 2021. The detailed schedule and talk information of this semester are as follows.
For inquiries or suggestions of future speakers, please contact the colloquium working group (Prof. Jane Lixin Dai, Prof. Tran Trung Luu, Prof. Yanjun Tu, Prof. Chenjie Wang, and Prof. Shizhong Zhang).
From the Outskirt of the Brightest Galaxies to Mapping the Darkest Universe
Speaker: Prof. Song HUANG
Affiliation: Tsinghua University
Date: February 5, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: Download
Abstract:
Modern imaging surveys such as Euclid, Vera Rubin’s LSST, and CSST will revolutionize our understanding of the Universe's bright and dark sides with deep imaging data and unprecedented weak gravitational lensing capabilities. In the last two decades, such a combination has demonstrated enormous potential to help us understand the physical connection between the galaxies and their dark matter halos. For example, I will introduce my research using data from the Subaru Telescope’s primary focus camera - HSC - to understand the assembly of the most massive galaxies in the Universe. We illustrate the intriguing connection between the extended, low-surface brightness stellar halo of low-redshift massive galaxies and the properties of their dark matter halos and will discuss its implication in cosmology. Meanwhile, a more precise picture of galaxy-halo connection and cosmology model heavily rely on our 3-D map of the Universe from large spectroscopic surveys. I will introduce the 6.5-m MUltiplexed Survey Telescope (MUST) - an ambitious Stage-V facility to conduct the next-generation cosmological redshift surveys to probe the high-redshift Universe and help us explore the primordial physics. I will briefly introduce the current engineering progress, the development of our international collaboration, the design of the instruments, and the preliminary cosmological forecast.
Key Reference:
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The Outer Stellar Mass of Massive Galaxies: A Simple Tracer of Halo Mass with Scatter Comparable to Richness and Reduced Projection Effects: https://arxiv.org/abs/2109.02646
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MUltiplexed Survey Telescope: Perspectives for Large-Scale Structure Cosmology in the Era of Stage-V Spectroscopic Survey: https://arxiv.org/abs/2411.07970
Tensor network simulation in strongly correlated systems: past, present and future
Speaker: Prof. Zhengcheng GU
Affiliation: Chinese University of Hong Kong
Date: February 19, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: Download
Abstract:
Tensor network states are new kinds of variational wavefunctions that help us to understand quantum phases and phase transitions beyond Landau paradigm In this talk, I will first review the major development of tensor network simulation in the past two decades In particular, I will introduce the novel concept of long range entanglement and entanglement renormalization Then I will discuss the major breakthroughs made by tensor network simulations in recent years If time permits, I will also mention the relationship between deep learning and tensor network simulation.
Key Reference:
- ZC Gu, XG Wen, Phys. Rev. B 80, 155131 (2009)
- ZC Gu, M Levin, XG Wen, Phys. Rev. B 78, 205116 (2008)
- S Yang, ZC Gu, XG Wen, Phys. Rev. Lett. 118, 110504 (2017)
- WY Liu, J Hasik, SS Gong, D Poilblanc, WQ Chen, ZC Gu, Phys. Rev. X 12, 031039 (2022)
TBC
Speaker: Prof. Dan KASEN
Affiliation: University of California, Berkeley
Date: March 5, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: TBC
Abstract: TBC
Key Reference: TBC
Hot-carrier cooling and relaxation processes in perovskites and semiconductor quantum dots
Speaker: Prof. Kam Sing WONG
Affiliation: The Hong Kong University of Science and Technology
Date: March 19, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: Download
Abstract:
Understanding and controlling the hot-carrier cooling and relaxation processes in semiconductor materials are very important to improve their optoelectronic devices performance such as solar cells, particularly under high current/carrier density condition.
Herein, we will report our recent works on transient absorption measurements to reveal the mechanism affecting the dynamics of hot-carrier cooling and the intricate competition among various ultrafast relaxation processes such as Auger effect, bandgap renormalization and free-carrier Stark effect for the excited carriers in perovskite films and semiconductor quantum dots.
TBC
Speaker: Prof. Shude MAO
Affiliation: Tsinghua University
Date: April 2, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: TBC
Abstract: TBC
Key Reference: TBC
TBC
Speaker: Prof. Ying LIU
Affiliation: The Pennsylvania State University
Date: April 16, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: TBC
Abstract: TBC
Key Reference: TBC
TBC
Speaker: Prof. Wenqing ZHANG
Affiliation: Southern University of Science and Technology
Date: April 30, 2025 (Wednesday)
Time: 5:00 p.m.
Venue: MWT4, 1/F, Meng Wah Complex, Main Campus, HKU, The University of Hong Kong
Poster: TBC
Abstract: TBC
Key Reference: TBC