Incoherent quantum algorithm dynamics of an open system with near-term devices

TL;DR

This paper proposes a variational quantum algorithm for simulating incoherent open system dynamics, including decoherence, using hybrid quantum-classical methods suitable for NISQ devices.

Contribution

It introduces a novel Lagrangian-based variational approach for simulating open quantum system dynamics via master equations on near-term quantum hardware.

Findings

The algorithm effectively simulates decoherence in open systems.

It demonstrates applicability to a wide range of incoherent dynamics.

The method leverages unitary operations to model non-unitary evolution.

Abstract

Hybrid quantum-classical algorithms are among the most promising systems to implement quantum computing under the Noisy-Intermediate Scale Quantum (NISQ) technology. In this paper, at first, we investigate a quantum dynamics algorithm for the density matrix obeying the von Neumann equation using an efficient Lagrangian-based approach. And then, we consider the dynamics of the ensemble-averaged of disordered quantum systems which is described by Hamiltonian ensemble with a hybrid quantum-classical algorithm. In a recent work [Phys. Rev. Lett. 120, 030403], the authors concluded that the dynamics of an open system could be simulated by a Hamiltonian ensemble because of nature of the disorder average. We investigate our algorithm to simulating incoherent dynamics (decoherence) of open system using an efficient variational quantum circuit in the form of master equations. Despite the non-unitary evolution of open systems, our method is applicable to a wide range of problems for incoherent dynamics with the unitary quantum operation.