Quantum algorithm for linear matrix equations

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Somma, Rolando D., Low, Guang Hao, Berry, Dominic W., Babbush, Ryan
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916911304933376
author Somma, Rolando D.
Low, Guang Hao
Berry, Dominic W.
Babbush, Ryan
author_facet Somma, Rolando D.
Low, Guang Hao
Berry, Dominic W.
Babbush, Ryan
contents We describe an efficient quantum algorithm for solving the linear matrix equation AX+XB=C, where A, B, and C are given complex matrices and X is unknown. This is known as the Sylvester equation, a fundamental equation with applications in control theory and physics. Our approach constructs the solution matrix X/x in a block-encoding, where x is a rescaling factor needed for normalization. This allows us to obtain certain properties of the entries of X exponentially faster than would be possible from preparing X as a quantum state. The query and gate complexities of the quantum circuit that implements this block-encoding are almost linear in a condition number that depends on A and B, and depend logarithmically in the dimension and inverse error. We show how our quantum circuits can solve BQP-complete problems efficiently, discuss potential applications and extensions of our approach, its connection to Riccati equation, and comment on open problems.
format Preprint
id arxiv_https___arxiv_org_abs_2508_02822
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantum algorithm for linear matrix equations
Somma, Rolando D.
Low, Guang Hao
Berry, Dominic W.
Babbush, Ryan
Quantum Physics
We describe an efficient quantum algorithm for solving the linear matrix equation AX+XB=C, where A, B, and C are given complex matrices and X is unknown. This is known as the Sylvester equation, a fundamental equation with applications in control theory and physics. Our approach constructs the solution matrix X/x in a block-encoding, where x is a rescaling factor needed for normalization. This allows us to obtain certain properties of the entries of X exponentially faster than would be possible from preparing X as a quantum state. The query and gate complexities of the quantum circuit that implements this block-encoding are almost linear in a condition number that depends on A and B, and depend logarithmically in the dimension and inverse error. We show how our quantum circuits can solve BQP-complete problems efficiently, discuss potential applications and extensions of our approach, its connection to Riccati equation, and comment on open problems.
title Quantum algorithm for linear matrix equations
topic Quantum Physics
url https://arxiv.org/abs/2508.02822