Optimized Amplitude Amplification for Quantum State Preparation

TL;DR

This paper introduces an optimized quantum state preparation algorithm that doubles the speed of previous methods by reducing oracle queries, enhancing efficiency for quantum algorithms handling large classical data.

Contribution

The authors develop a novel amplitude amplification technique that significantly decreases the number of oracle queries needed for quantum state preparation.

Findings

Achieves twice the speed of existing algorithms

Reduces the number of oracle queries required

Improves efficiency of quantum algorithms for large data sets

Abstract

In this paper, we present an algorithm for preparing quantum states of the form $\sum_{i=0}^{n-1} \alpha_i |i\rangle$, where the coefficients $\alpha_i$ are specified by a quantum oracle. Our method achieves this task twice as fast as the best existing algorithm known to the authors. Such state preparation is essential for quantum algorithms that process large classical inputs, including matrix inversion and linear system solvers. The standard approach relies on amplitude amplification, a process that may require multiple, time-consuming oracle queries. Consequently, reducing the number of queries - and thereby the overall time complexity can lead to significant performance improvements in practice.