Minimizing entanglement entropy for enhanced quantum state preparation

TL;DR

This paper introduces a two-step quantum state preparation method that minimizes entanglement entropy to enable more efficient and accurate state encoding on NISQ devices.

Contribution

The authors propose a novel approach that reduces entanglement entropy before state representation, improving quantum state preparation efficiency and accuracy.

Findings

Reduced entanglement entropy leads to easier state preparation.

The method achieves high accuracy in preparing states with 6-20 qubits.

Benchmark results demonstrate effectiveness on 2D normal distribution and Ricker wavelet states.

Abstract

Quantum state preparation is an important subroutine in many quantum algorithms. The goal is to encode classical information directly to the quantum state so that it is possible to leverage quantum algorithms for data processing. However, quantum state preparation of arbitrary states scales exponentially in the number of two-qubit gates, and this makes quantum state preparation a very difficult task on quantum computers, especially on near-term noisy devices. This represents a major challenge in achieving quantum advantage. We present and analyze a novel two-step state preparation method where we first minimize the entanglement entropy of the target quantum state, thus transforming the state to one that is easier to prepare. The state with reduced entanglement entropy is then represented as a matrix product state, resulting in a high accuracy preparation of the target state. Our method is suitable for NISQ devices and we give rigorous lower bounds on the accuracy of the prepared state in terms of the entanglement entropy. We benchmark our method with 2D normal distribution and Ricker wavelet states with 6--20 qubits.