Hardware-efficient variational quantum algorithms for time evolution

TL;DR

This paper introduces hardware-efficient variational algorithms for simulating quantum system time evolution, reducing hardware demands and improving accuracy without matrix inversion, suitable for near-term quantum devices.

Contribution

The paper proposes new variational algorithms for real and imaginary time evolution that are more hardware-efficient and do not require matrix inversion, advancing quantum simulation capabilities.

Findings

Significant reduction in hardware requirements for imaginary time evolution.

Algorithms of increasing accuracy for real time evolution.

Numerical validation on quantum Hamiltonians with local interactions.

Abstract

Parameterized quantum circuits are a promising technology for achieving a quantum advantage. An important application is the variational simulation of time evolution of quantum systems. To make the most of quantum hardware, variational algorithms need to be as hardware-efficient as possible. Here we present alternatives to the time-dependent variational principle that are hardware-efficient and do not require matrix inversion. In relation to imaginary time evolution, our approach significantly reduces the hardware requirements. With regards to real time evolution, where high precision can be important, we present algorithms of systematically increasing accuracy and hardware requirements. We numerically analyze the performance of our algorithms using quantum Hamiltonians with local interactions.