Many quantum algorithms are developed to evaluate eigenvalues for Hermitian matrices. However, few practical approach exists for the eigenanalysis of nonHermintian ones, such as arising from modern power systems. The main difficulty lies in the fact that, as the eigenvector matrix of a general matrix can be nonunitary, solving a general eigenvalue problem is inherently incompatible with existing unitarygatebased quantum methods. To fill this gap, this paper introduces a Variational Quantum Universal Eigensolver (VQUE), which is deployable on noisy intermediate scale quantum computers. Our new contributions include: (1) The first universal variational quantum algorithm capable of evaluating the eigenvalues of nonHermitian matrices—Inspired by Schur’s triangularization theory, VQUE unitarizes the eigenvalue problem to a procedure of searching unitary transformation matrices via quantum devices; (2) A Quantum Process Snapshot technique is devised to make VQUE maintain the potential quantum advantage inherited from the original variational quantum eigensolver—With additional
 Award ID(s):
 1839136
 NSFPAR ID:
 10475599
 Publisher / Repository:
 Quantum Journal
 Date Published:
 Journal Name:
 Quantum
 Volume:
 7
 ISSN:
 2521327X
 Page Range / eLocation ID:
 1040
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
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