Trotterless Simulation of Open Quantum Systems for NISQ Quantum Devices

TL;DR

This paper introduces a novel simulation method for open quantum systems on NISQ devices that uses Kraus operator series, potentially offering more efficient and depth-independent circuits compared to traditional Trotterization.

Contribution

The paper presents a new Kraus-based simulation approach that can generate constant-depth circuits for certain open quantum systems, improving scalability on NISQ hardware.

Findings

The method produces circuits of time-independent depth for specific systems.

It offers an alternative to Trotterization with potentially better scalability.

Applicable to a class of open quantum systems on NISQ devices.

Abstract

The simulation of quantum systems is one of the flagship applications of near-term NISQ (noisy intermediate-scale quantum) computing devices. Efficiently simulating the rich, non-unitary dynamics of open quantum systems remains challenging on NISQ hardware. Current simulation methods for open quantum systems employ time-stepped Trotter product formulas ("Trotterization") which can scale poorly with respect to the simulation time and system dimension. Here, we propose a new simulation method based on the derivation of a Kraus operator series representation of the system. We identify a class of open quantum systems for which this method produces circuits of time-independent depth, which may serve as a desirable alternative to Trotterization, especially on NISQ devices.