Simulating noisy quantum channels via quantum state preparation algorithms

TL;DR

This paper introduces a simplified method for simulating quantum channels on quantum computers using quantum state preparation algorithms, broadening applicability to various systems and states, with demonstrations on IBM quantum hardware.

Contribution

The authors propose a straightforward approach to simulate quantum channels via quantum state preparation, avoiding complex non-linear equation solutions required by previous algorithms.

Findings

Effective simulation of qubit and qudit quantum channels.

Successful implementation on IBM quantum computers.

Versatile application to Lorentz transformations and mixed states.

Abstract

In Refs. [Phys. Rev. A 96, 062303 (2017)] and [Sci. China Phys. Mech. Astron. 61, 70311 (2018)], the authors reported an algorithm to simulate, in a circuit-based quantum computer, a general quantum channel (QC). However, the application of their algorithm is limited because it entails the solution of intricate non-linear systems of equations in order to obtain the quantum circuit to be implemented for the simulation. Motivated by this issue, in this article we identify and discuss a simple way to implement the simulation of QCs on any $d$-level quantum system through quantum state preparation algorithms, that have received much attention in the quantum information science literature lately. We exemplify the versatility of our protocol applying it to most well known qubit QCs, to some qudit QCs, and to simulate the effect of Lorentz transformations on spin states. We also regard the application of our protocol for initial mixed states. Most of the given application examples are demonstrated using IBM's quantum computers.