Hybrid spin-superconducting quantum circuit mediated by deterministically prepared entangled photonic states

TL;DR

This paper proposes a hybrid quantum system integrating nitrogen vacancy centers and a tunable flux qubit mediated by entangled microwave photons in a nonlinear superconducting resonator, enhancing coherence and entanglement.

Contribution

It introduces a novel hybrid quantum architecture utilizing entangled microwave photons and nonlinear wave-mixing to improve coherence and entanglement in quantum systems.

Findings

Increased coherence time and fidelity stabilization.

Enhanced entanglement strength.

Effective mediation of interactions via entangled photons.

Abstract

In hybrid quantum systems a controllable coupling can be obtained by mediating the interactions with dynamically introduced photons. We propose a hybrid quantum architecture consisting of two nitrogen vacancy center ensembles coupled to a tunable flux qubit; that are contained on the transmission line of a multimode nonlinear superconducting coplanar waveguide resonator with an appended Josephson mixing device. We discuss using entangled propagating microwaves photons, which through our nonlinear wave-mixing procedure are made into macroscopically distinct quantum states. We use these states to steer the system and show that with further amplification we can create a similar photonic state, which has a more distinct reduction of its uncertainty. Furthermore, we show that all of this leads to a lengthened coherence time, a reasonable fidelity which decays to 0.94 and then later increases upward to stabilize at 0.6 as well as a strengthened entanglement.