Title:Towards practical Hamiltonian simulation

Speaker: Qi Zhao，the University of Hongkong

Time:2024-12-27 10：00 

Venue:Room W105,  Physics Building

Abstract:Quantum simulation, as one of the most promising applications of quantum computers, can help simulate the evolution of complex quantum systems, thus helping to solve many problems in the fields of condensed matter physics, high-energy physics, quantum chemistry. However, there is still a long way to go for quantum simulation to be practically applied. Hamiltonian simulation algorithms are a type of systematic and reliable quantum simulation algorithms. The error analysis of such algorithms is a crucial issue in this field, as it determines the estimation of quantum circuit depth in quantum computing tasks. The mainstream error analysis often only measures the initial state and observables in the worst-case scenario, which greatly overestimates the error in quantum algorithms and hinders the practical application of quantum simulation. To address this issue, we considered the impact of the initial state and measurement on error analysis in quantum simulation tasks, and proposed the analysis of quantum simulation algorithms based on random initial state [PRL 129 (27), 270502, QIP22 talk], entangled state [arXiv:2406.02379, QIP 25 talk], and local observables [arXiv:2407.14497]. These results greatly reduce the resource requirements in quantum simulation tasks, promoting the future implementation and application of quantum simulation algorithms.

Bio:Dr. Qi Zhao is an Assistant Professor in the Department of Computer Science, the University of Hongkong (HKU). In 2024, he was recognized as one of the MIT Technology Review “Innovators Under 35” for the Asia Pacific Region. His research interests include quantum simulation, quantum computing, quantum information, and entanglement detection. He obtained a Bachelor’s and Doctoral degree from Tsinghua University in 2014 and 2018 respectively. He was a postdoctoral researcher at the University of Science and Technology of China in 2019. He was a Hartree Postdoctoral Fellow at the University of Maryland in the United States before joining HKU as Assistant Professor in 2022. He has published 45 journal articles, including Nature, PRL, PRX, npj Quantum Information, PNAS, and IEEE TIT. His works have also been presented as contributed talks at important conferences in quantum information theory, such as QIP, AQIS, TQC, and QCrypt, and he has served as a program committee member (PC member) for AQIS.