Probabilistic Nonunitary Gate in Imaginary Time Evolution

TL;DR

This paper introduces a probabilistic method leveraging Grover's algorithm to implement nonunitary operations on quantum computers, enhancing success probability for imaginary time evolution and tensor network contraction tasks.

Contribution

It extends probabilistic nonunitary operation implementation using Grover's algorithm, improving success rates without fidelity loss in quantum simulations.

Findings

Success probability increases with the proposed method.

Applicable to imaginary time evolution and tensor network contraction.

No decrease in fidelity during nonunitary operation implementation.

Abstract

Simulation of quantum matters is a significant application of quantum computers. In contrast to the unitary operation which can be realized naturally on a quantum computer, the implementation of nonunitary operation, widely used in classical approaches, needs special designing. Here, by application of Grover's algorithm, we extend the probabilistic method of implementing nonunitary operation and show that it can promote success probability without fidelity decreasing. This method can be applied to problems of imaginary time evolution and contraction of tensor networks on a quantum computer.