Black-box quantum state preparation without arithmetic

TL;DR

This paper introduces a novel quantum state preparation algorithm that eliminates the need for arithmetic, significantly reducing gate complexity and advancing the feasibility of quantum simulations.

Contribution

The authors develop a new arithmetic-free quantum state preparation method that greatly reduces gate complexity compared to previous techniques.

Findings

Reduces gate count by a factor of 286-374 for realistic precision

Improves efficiency of quantum state preparation in quantum simulations

Brings practical quantum simulation closer to reality

Abstract

Black-box quantum state preparation is an important subroutine in many quantum algorithms. The standard approach requires the quantum computer to do arithmetic, which is a key contributor to the complexity. Here we present a new algorithm that avoids arithmetic. We thereby reduce the number of gates by a factor of 286-374 over the best prior work for realistic precision; the improvement factor increases with the precision. As quantum state preparation is a crucial subroutine in many approaches to simulating physics on a quantum computer, our new method brings useful quantum simulation closer to reality.