Journal Article

FZJ-2025-04031

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Quantum algorithm for Green's-function measurements in the Fermi-Hubbard model

Bishop, G. (Corresponding author)FZJ* ; Bagrets, D.FZJ* ; Wilhelm, F. K.

2025
Inst. Woodbury, NY

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Please use a persistent id in citations: doi:10.1103/PhysRevA.111.062610  doi:10.34734/FZJ-2025-04031

Abstract: In the framework of the hybrid quantum-classical variational cluster approach to strongly correlated electron systems one of the goals of a quantum subroutine is to find single-particle correlation functions of lattice fermions in polynomial time. Previous works suggested to use variants of the Hadamard test for this purpose, which requires an implementation of controlled single-particle fermionic operators. However, for a number of locality-preserving mappings to encode fermions into qubits, a direct construction of such operators is not possible. In this work, we propose a quantum algorithm that uses an analog of the Kubo formula adapted to a quantum circuit simulating the Hubbard model. It allows to access the Green's function of a cluster directly using only bilinears of fermionic operators and circumvents the usage of the Hadamard test. We test our algorithm in practice by using open-access simulators of noisy IBM superconducting chips.

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Contributing Institute(s):

1. Quantum Computing Analytics (PGI-12)

Research Program(s):

1. 5223 - Quantum-Computer Control Systems and Cryoelectronics (POF4-522) (POF4-522)

Appears in the scientific report 2025

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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