Digital quantum simulation of open quantum systems using quantum imaginary time evolution

TL;DR

This paper introduces algorithms for simulating open quantum systems governed by Lindblad equations on digital quantum computers, demonstrating their effectiveness through experiments on IBM Quantum hardware.

Contribution

It adapts the quantum imaginary time evolution algorithm to simulate non-unitary open system dynamics, a novel approach in quantum simulation.

Findings

Successful simulation of spontaneous emission on IBM Quantum hardware

Demonstration of dissipative transverse field Ising model dynamics

Advancement in open quantum system simulation techniques

Abstract

Quantum simulation on emerging quantum hardware is a topic of intense interest. While many studies focus on computing ground state properties or simulating unitary dynamics of closed systems, open quantum systems are an interesting target of study owing to their ubiquity and rich physical behavior. However, their non-unitary dynamics are also not natural to simulate on digital quantum devices. Here, we report algorithms for the digital quantum simulation of the dynamics of open quantum systems governed by a Lindblad equation using adaptations of the quantum imaginary time evolution (QITE) algorithm. We demonstrate the algorithms on IBM Quantum's hardware with simulations of the spontaneous emission of a two level system and the dissipative transverse field Ising model. Our work advances efforts to simulate the dynamics of open quantum systems on quantum hardware.