Co-Designed Adaptive Quantum State Preparation Protocols

TL;DR

This paper introduces Co-ADAPT-VQE, a quantum state preparation protocol that optimizes circuits considering hardware constraints, significantly reducing CNOT gate counts for various device connectivities and system sizes.

Contribution

It presents a co-designed framework for adaptive quantum state preparation that accounts for hardware limitations, improving efficiency over existing methods.

Findings

Up to 97% reduction in CNOT count for 12-14 qubit systems.

Over 70% CNOT reduction compared to original ADAPT-VQE with all-to-all connectivity.

Effective for devices with linear nearest-neighbor connectivity.

Abstract

We propose a co-designed variant of ADAPT-VQE (Co-ADAPT-VQE) where the quantum hardware is taken into account in the construction of the ansatz. This framework can be readily used to optimize state preparation circuits for any device, addressing shortcomings such as limited connectivity, short coherence times, and variable gate errors. We exemplify the impact of Co-ADAPT-VQE by creating state preparation circuits for devices with linear nearest-neighbor (LNN) connectivity. We show a reduction of the CNOT count of the final circuits by up to 97% for 12-14 qubit systems, with the impact being greater for larger and more strongly correlated systems. Surprisingly, the circuits created by Co-ADAPT-VQE provide an over 70% CNOT count reduction with respect to the original ADAPT-VQE in all-to-all connectivity, despite being restricted to LNN qubit interactions.