Quantum Simulation of Generic Many-Body Open System Dynamics Using Classical Noise

TL;DR

This paper presents a method for simulating many-body open quantum system dynamics using classical noise, enabling the study of decoherence processes in various quantum platforms.

Contribution

It introduces a stochastic Hamiltonian approach to emulate open system dynamics, including both Markovian and non-Markovian behaviors, with scalable fidelity decay analysis.

Findings

Noise-averaged density matrix simulates open dynamics with k-body Lindblad operators.

Fidelity decay scales as N^{-2k} with system size N.

Method applicable to optical lattices, superconducting circuits, and trapped ions.

Abstract

We introduce a scheme for the quantum simulation of many-body decoherence based on the unitary evolution of a stochastic Hamiltonian. Modulating the strength of the interactions with stochastic processes, we show that the noise-averaged density matrix simulates an effectively open dynamics governed by $k$-body Lindblad operators. Markovian dynamics can be accessed with white-noise fluctuations; non-Markovian dynamics requires colored noise. The time scale governing the fidelity decay under many-body decoherence is shown to scale as $N^{-2k}$ with the system size $N$. Our proposal can be readily implemented in a variety of quantum platforms including optical lattices, superconducting circuits and trapped ions.