https://doi.org/10.1140/epjs/s11734-025-01627-7
Regular Article
Improved quantum linear system solver via quantum phase discrimination
1
Institute of Quantum Computing and Software, School of Computer Science and Engineering, Sun Yat-sen University, 510006, Guangzhou, China
2
Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), 518045, Shenzhen, China
Received:
2
December
2024
Accepted:
7
April
2025
Published online:
24
April
2025
The problem of solving linear systems is of great significance in both theory and practice, for which quantum solvers have been shown to provide an exponential speedup over the best-known classical solvers. Recently, a quantum linear system solver has been developed with the state-of-the-art complexity [1], which combines two techniques, namely, discrete adiabatic evolution and eigenstate filtering. However, the parameters of the quantum circuit for eigenstate filtering need to be precomputed classically via the discrete Fourier transform, which introduces additional computational overhead. In this paper, we improve the solver by presenting a new eigenstate filtering process termed quantum phase discrimination in which the circuit parameters are given directly in a concise and analytical form with negligible classical overhead, while maintaining the same quantum complexity.
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© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
