2022/08/01 by Souichi Takahira, A. Ohashi, Tomohiro Sogabe +1 · 1 voice · 2 citations
Computer Science · #Matrix Theory and Algorithms #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography
paper · doi:10.26421/qic22.11-12-4
openalex publication_date 2022/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
he matrix functions can be defined by Cauchy's integral formula and can be approximated by the linear combination of inverses of shifted matrices using a quadrature formula. In this paper, we propose a quantum algorithm for matrix functions based on a procedure to implement the linear combination of the inverses on quantum computers. Compared with the previous study [S. Takahira, A. Ohashi, T. Sogabe, and T.S. Usuda, Quant. Inf. Comput., 20, 1&2, 14--36, (Feb. 2020)] that proposed a quantum algorithm to compute a quantum state for the matrix function based on the circular contour centered at the origin, the quantum algorithm in the present paper can be applied to a more general contour. Moreover, the algorithm is described by the block-encoding framework. Similarly to the previous study, the algorithm can be applied even if the input matrix is not a Hermitian or normal matrix. This is an advantage compared with quantum singular value transformation.