Title: Flexibility of the factorized form of the unitary coupled cluster Ansatz

Journal Article · · Journal of Chemical Physics
DOI: https://doi.org/10.1063/5.0074311 · OSTI ID:1978998

The factorized form of the unitary coupled cluster Ansatz is a popular state preparation Ansatz for electronic structure calculations of molecules on quantum computers. It is often viewed as an approximation (based on the Trotter product formula) for the conventional unitary coupled cluster operator. In this work, we show that the factorized form is quite flexible, allowing one to range from a conventional configuration interaction, to conventional unitary coupled cluster, to efficient approximations that lie in between these two. The variational minimization of the energy often allows simpler factorized unitary coupled cluster approximations to achieve high accuracy, even if they do not accurately approximate the Trotter product formula. This is similar to how quantum approximate optimization algorithms can achieve high accuracy with a small number of levels.

Research Organization:
University of California, Oakland, CA (United States); University of Florida, Gainesville, FL (United States)
Sponsoring Organization:
Georgetown University; National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES); University of Florida
Grant/Contract Number:
AC02-05CH11231; SC0019330
OSTI ID:
1978998
Journal Information:
Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 4 Vol. 156; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

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