Weak measurement and control of entanglement generation

TL;DR

This paper demonstrates how weak joint measurement and local feedback can effectively control entanglement between two qubits by utilizing a decoherence free subspace, enabling rapid entanglement generation or suppression.

Contribution

It introduces a method combining weak measurement and feedback to control entanglement via a decoherence free subspace, highlighting differences between purification and entanglement generation.

Findings

Weak measurement and feedback can rapidly drive the system into a decoherence free subspace.

Feedback can generate or suppress entanglement dynamically.

The approach distinguishes between purification and entanglement generation processes.

Abstract

In this paper we show how weak joint measurement and local feedback can be used to control entanglement generation between two qubits. To do this, we make use of a decoherence free subspace (DFS). Weak measurement and feedback can be used to drive the system into this subspace rapidly. Once within the subspace, feedback can generate entanglement rapidly, or turn off entanglement generation dynamically. We also consider, in the context of weak measurement, some of differences between purification and generating entanglement.