Journal Article

PUBDB-2025-00812

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Estimation of Quantum Fisher Information via Stein's Identity in Variational Quantum Algorithms

Halla, M. (Corresponding author)DESY*

2025
Wien Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften

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Please use a persistent id in citations: doi:10.48550/ARXIV.2502.17231  doi:10.22331/q-2025-07-21-1798  doi:10.3204/PUBDB-2025-00812

Report No.: arXiv:2502.17231

Abstract: The Quantum Fisher Information Matrix (QFIM) plays a crucial role in quantum optimization algorithms such as Variational Quantum Imaginary Time Evolution and Quantum Natural Gradient Descent. However, computing the full QFIM incurs a quadratic computational cost of O(d^2) with respect to the number of parameters d, limiting its scalability for high-dimensional quantum systems. To address this limitation, stochastic methods such as the Simultaneous Perturbation Stochastic Approximation (SPSA) have been employed to reduce computational complexity to a constant (Quantum 5, 567 (2021)). In this work, we propose an alternative estimation framework based on Stein's identity that also achieves constant computational complexity. Furthermore, our method reduces the quantum resources required for QFIM estimation compared to the SPSA approach. We provide numerical examples using the transverse-field Ising model and the lattice Schwinger model to demonstrate the feasibility of applying our method to realistic quantum systems.

Keyword(s): Quantum Physics (quant-ph) ; FOS: Physical sciences

Note: German Ministry of Education and Research (BMBF) under project NiQ (Grant No. 13N16203)

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Contributing Institute(s):

1. Centre f. Quantum Techno. a. Application (CQTA)
2. Externes Institut (Extern)
3. Temporary IAM group (DESY)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2025

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Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; IF >= 5 ; JCR ; SCOPUS ; Web of Science Core Collection

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