Optimizing Quantum Entanglement Preservation in a Qubit-Qubit System with Dzyaloshinskii Moriya Interaction under Noisy Magnetic Fields via Feedback Control

TL;DR

This paper develops a feedback control method to preserve quantum entanglement in a noisy qubit system with Dzyaloshinskii Moriya interaction, significantly improving quantum sensing capabilities under environmental noise.

Contribution

It introduces a stochastic Lindblad model and a dynamic feedback protocol to maintain entanglement, enhancing quantum sensing performance in noisy environments.

Findings

Feedback doubles the average negativity from 0.21 to 0.42.

Enhanced entanglement leads to a 2.4-fold improvement in quantum sensitivity.

The method effectively protects entanglement against stochastic magnetic noise.

Abstract

Quantum entanglement is a key resource for quantum information processing and sensing, but it is severely degraded by environmental noise. We extend the previous study by Moosavi Khansari and Kazemi Hasanvand [27] of entanglement dynamics in a qubit qubit system with Dzyaloshinskii Moriya (DM) interaction and static magnetic fields to the realistic case of time varying, stochastic magnetic fields. We derive a stochastic Lindblad master equation and simulate quantum trajectories to quantify the negativity under colored noise. We then design a proportional integral feedback protocol that dynamically adjusts the DM interaction strength D_z (t) to maintain negativity near a target value. The feedback stabilized state is used as a probe for quantum metrology: we compute the quantum Fisher information (QFI) for estimating an unknown static field B_0. Our simulations show that feedback increases the time averaged negativity from 0.21 to 0.42 for {\alpha}=1 at noise amplitude {\sigma}=0.5, leading to a factor 2.4 improvement in sensitivity over the classical shot noise limit. This work provides a practical route to protect entanglement in noisy environments and enhances quantum sensing performance.