Subspace projection method for unstructured searches with noisy quantum oracles using a signal-based quantum emulation device

TL;DR

This paper introduces a classical signal-based emulation method for unstructured search problems that uses subspace projections, offering higher success probabilities than Grover's algorithm under noisy conditions.

Contribution

It presents a novel classical emulation approach employing subspace projections to enhance unstructured search efficiency with noisy quantum oracles.

Findings

Higher success probability than Grover's algorithm for the same number of oracle calls.

Demonstrates potential computational advantages despite bandwidth limitations.

Applicable to problems of limited size with noisy quantum oracles.

Abstract

This paper describes a novel approach to solving unstructured search problems using a classical, signal-based emulation of a quantum computer. The classical nature of the representation allows one to perform subspace projections in addition to the usual unitary gate operations. Although bandwidth requirements will limit the scale of problems that can be solved by this method, it can nevertheless provide a significant computational advantage for problems of limited size. In particular, we find that, for the same number of noisy oracle calls, the proposed subspace projection method provides a higher probability of success for finding a solution than does an single application of Grover's algorithm on the same device.