Robust quantum state recovery from amplitude damping within a mixed states framework

TL;DR

This paper presents a method to nearly fully restore two-qubit mixed quantum states affected by amplitude damping, using a reversal procedure with CNOT and Hadamard gates, and introduces a robust recovery approach under system uncertainties.

Contribution

It introduces a novel reversal procedure for amplitude damping in two-qubit mixed states and a robust recovery method accounting for uncertainties.

Findings

High fidelity recovery of quantum states post-damping

Protection of entanglement during the recovery process

Effective robust recovery under system uncertainties

Abstract

Due to the interaction with the environment, a quantum state is subjected to decoherence which becomes one of the biggest problems for practical quantum computation. Amplitude damping is one of the most important decoherence processes. Here, we show that general two-qubit mixed states undergoing an amplitude damping can be almost completely restored using a reversal procedure. This reversal procedure through CNOT and Hadamard gates, could also protect the entanglement of two-qubit mixed states, when it undergoes general amplitude damping. Moreover, in the presence of uncertainty in the underlying system, we propose a robust recovering method with optimal characteristics of the problem.