时间：2025年6月26日下午14:30-16:00

Time: 14:30-16:00, Thursday, June 26, 2025

主持人：西湖大学物理系PI 严正

Host: Dr. Zheng Yan, PI of School of Science, Westlake University

地点：云谷校区E10-211

Venue: E10-211, Yungu Campus, Westlake University

报告语言：中文

Lecture Language: Chinese

Prof. Xiao-Peng Li,

Professor of physics in the Physics Department of Fudan University

E-mail: xiaopeng_li@fudan.edu.cn

主讲人/Speaker:

Xiaopeng Li is professor of physics in the Physics Department of Fudan University, China, jointly employed by Shanghai Qi Zhi Institute. He is active in quantum information science and condensed-matter theories, with his primary research interests in exploiting the quantum computation power of various quantum simulation platforms. He received his Ph.D. in physics from the University of Pittsburgh in 2013 and joined Fudan University as a faculty member in 2016 after three years at the University of Maryland, supported by a Joint Quantum Institute theoretical postdoctoral fellowship. He has been a full professor since 2019. His current focus is on neutral atom quantum computing and potential applications.

摘要/Abstract:

Digital quantum simulations are among the most promising in accomplishing practical quantum advantage in near term. In the last several years, we have developed a quantum kernel function expansion (QKFE) approach for digital quantum simulations of thermodynamics, of direct relevance in simulating quantum chemistry and quantum magnetism by quantum circuits. In this quantum algorithm, the many-body density of states is approximated by a kernel-Fourier expansion, whose expansion moments are obtained by random state sampling and quantum interferometric measurements. As compared to its classical counterpart, namely the kernel polynomial method (KPM), QKFE has an exponential advantage in the cost of both time and memory. In computing low temperature properties, QKFE becomes inefficient, as similar to classical KPM. To resolve this difficulty, we further construct a thermal ensemble and approaches the low temperature regime step-by-step. For quantum Hamiltonians, whose ground states are preparable with polynomial quantum circuits, THEI has an overall polynomial complexity. We demonstrate its efficiency with applications to one and two-dimensional quantum spin models, and a fermionic lattice. This algorithm has been tested on Zuchongzhi quantum processors, where phase transition criticality at finte temperature has been demonstrated for transverse field Ising and XY models.

联系人/Contact:

School of Science, Wenwen Cheng, Email: chengwenwen@westlake.edu.cn