Title: [Joint CQSE & NCTS Special Seminar] ​Simulating large-size quantum spin chains on cloud quantum computers
Speaker: Prof. Tzu-Chieh Wei (Stony Brook University)
Time: 2023/08/04 (Fri.) 14:30-15:30
Place: NCTS Physics Lecture Hall, 4F, Chee-Chun Leung Cosmology Hall, NTU
Online: https://nationaltaiwanuniversity-zbh.my.webex.com/nationaltaiwanuniversity-zbh.my/j.php?MTID=m43f3d7c2424295d838f7f536071a69d0

Abstract:
​Quantum computers have the potential to efficiently simulate other quantum systems, especially when their size is large and classical simulation is not feasible. Despite the total qubit number reaching beyond one hundred in several existing quantum devices, their applicability is still plagued by the prevalent noise and errors. Here we present an analysis of a physics-motivated variational ansatz for the XXZ spin chain and report realizations on various IBM quantum computers to simulate ground states of quantum spin chains with qubit numbers ranging from 4 to 102. The estimated ground-state energies from these experiments across different backends and with varying sizes of system reach the expected values within a few error percentages. The enabling factors for accurate large realizations include the use of short-depth physics-motivated ansatzes and efficient and scalable energy measurement and error mitigation, particularly using a reference state in the zero-noise extrapolation.

Ref: Phys. Rev. Research 5, 013183 (2023)

Biography:
Education
PhD   Physics, University of Illinois at Urbana-Champaign (UIUC), October 2004
M. S.  Physics, National Taiwan University (NTU), June 1996
B. A.  Physics, National Taiwan University, June 1994

Positions and Related Experience
Professor, SUNY-SB Sep 2022 - present
Associate Professor, SUNY-SB Sep 2017 - Aug 2022
Assistant Professor, SUNY-SB Sep 2011 - Aug 2017
Research Associate, UBC Nov 2010 - Sep 2011
Postdoctoral Research Fellow, UBC Sep 2009 - Nov 2010
Postdoctoral Research Fellow, IQC Sep 2007 - Aug 2009
Postdoctoral Research Associate, UIUC Sep 2004 - Aug 2007 
Graduate Research Assistant, UIUC 2001 - 2004 
Graduate Research Assistant, NTU 1994 - 1996