Impossibility of a Quantum Speed-up with a Faulty Oracle

TL;DR

This paper demonstrates that when oracle calls in Grover's search are prone to small failures, the quantum speed-up advantage disappears, making quantum and classical search equally effective.

Contribution

It proves that a quantum speed-up is impossible for Grover's search with faulty oracles, extending understanding of quantum algorithm limitations.

Findings

Quantum speed-up is nullified by oracle failures

Faulty oracles prevent quantum advantage in search

Classical and quantum search perform similarly under faults

Abstract

We consider Grover's unstructured search problem in the setting where each oracle call has some small probability of failing. We show that no quantum speed-up is possible in this case.