Validating and controlling quantum enhancement against noise by motion of a qubit

TL;DR

This paper demonstrates that controlling the motion of a traveling atom qubit inside a leaky cavity can enhance quantum coherence and entanglement, especially at higher velocities, by optimizing measurement strategies.

Contribution

It introduces a method to optimize quantum witness measurements for moving qubits, showing motion control as a means to protect and enhance quantum traits against noise.

Findings

Higher qubit velocities extend quantum coherence lifetime.

Optimized measurements improve quantum witness reliability.

Qubit motion acts as a quantum enhancer against noise.

Abstract

Experimental validation and control of quantum traits for an open quantum system are important for any quantum information purpose. We consider a traveling atom qubit as a quantum memory with adjustable velocity inside a leaky cavity, adopting a quantum witness as a figure of merit for quantumness assessment. We show that this model constitutes an inherent physical instance where the quantum witness does not work properly if not suitably optimized. We then supply the optimal intermediate blind measurements which make the quantum witness a faithful tester of quantum coherence. We thus find that larger velocities protect quantumness against noise, leading to lifetime extension of hybrid qubit-photon entanglement and to higher phase estimation precision. Control of qubit motion thus reveals itself as a quantum enhancer.