Efficient Classical Processing of Constant-Depth Time Evolution Circuits in Control Hardware

TL;DR

This paper introduces a hardware-assisted classical processing method called parameterized circuit execution (PCE) to significantly reduce compilation time for quantum many-body system simulations, improving efficiency of near-term quantum algorithms.

Contribution

The work extends PCE to compute dynamical properties of quantum systems using constant-depth circuits, demonstrating up to 50% reduction in classical processing time for spin models.

Findings

Up to 50% reduction in classical processing time.

Effective for spin-spin correlation functions in transverse field XY and Heisenberg models.

Applicable to constant-depth time evolution circuits in control hardware.

Abstract

Improving quantum algorithms run-time performance involves several strategies such as reducing the quantum gate counts, decreasing the number of measurements, advancement in QPU technology for faster gate operations, or optimizing the classical processing. This work focuses on the latter, specifically reducing classical processing and compilation time via hardware-assisted parameterized circuit execution (PCE) for computing dynamical properties of quantum systems. PCE was previously validated for QCVV protocols, which leverages structural circuit equivalencies. We demonstrate the applicability of this approach to computing dynamical properties of quantum many-body systems using structurally equivalent time evolution circuits, specifically calculating correlation functions of spin models using constant-depth circuits generated via Cartan decomposition. Implementing this for spin-spin correlation functions in Transverse field XY (up to 6-sites) and Heisenberg spin models (up to 3-sites), we observed a run-time reduction of up to 50\% compared to standard compilation methods. This highlights the adaptability of time-evolution circuit with hardware-assisted PCE to potentially mitigate the classical bottlenecks in near-term quantum algorithms.