Deterministic creation and stabilization of entanglement in circuit QED by homodyne-mediated feedback control

TL;DR

This paper demonstrates a method using homodyne measurement and feedback control in circuit QED to reliably create and stabilize entangled two-qubit states despite environmental noise.

Contribution

It introduces an improved filtered-current-based feedback scheme for better entanglement stabilization in circuit QED systems.

Findings

Homodyne-mediated feedback effectively creates entanglement.

Filtered-current feedback enhances stabilization under noise.

The method is feasible in current circuit QED setups.

Abstract

In the solid-state circuit QED system and based on the homodyne measurement in dispersive regime, we demonstrate that a homodyne-current-based feedback can create and stabilize highly entangled two-qubit states in the presence of moderate noisy environment. Particularly, we present an extended analysis for the current-based Markovian feedback, which leads to an improved filtered-current-based feedback scheme. We show that this is essential for us to achieve the desirable control effect in present system.