Suppressing decoherence and improving entanglement by quantum-jump-based feedback control in two-level systems

TL;DR

This paper investigates how quantum-jump-based feedback control can enhance entanglement and extend coherence times in a two-qubit system where one qubit experiences decoherence, relevant for solid-state quantum systems.

Contribution

It demonstrates that quantum-jump-based feedback control can effectively improve entanglement and prolong coherence in two-qubit systems affected by decoherence.

Findings

Feedback control enhances entanglement between qubits.

Prolongs coherence time of the decohering qubit.

Numerical simulations confirm effectiveness.

Abstract

We study the quantum-jump-based feedback control on the entanglement shared between two qubits with one of them subject to decoherence, while the other qubit is under the control. This situation is very relevant to a quantum system consisting of nuclear and electron spins in solid states. The possibility to prolong the coherence time of the dissipative qubit is also explored. Numerical simulations show that the quantum-jump-based feedback control can improve the entanglement between the qubits and prolong the coherence time for the qubit subject directly to decoherence.