Phase transition of light in circuit QED lattices coupled to nitrogen-vacancy centers in diamond

TL;DR

This paper proposes a hybrid quantum system combining superconducting resonators and nitrogen-vacancy centers to simulate phase transitions between photonic Mott insulator and superfluid states, with tunable parameters and feasible experimental implementation.

Contribution

It introduces a novel hybrid circuit-QED architecture enabling controllable quantum phase transitions in a 2D lattice with practical tunability and analysis methods.

Findings

Phase boundary determined via mean-field approach.

Dissipative effects modeled with quantum jump technique.

Architecture offers good tunability and feasible experimental realization.

Abstract

We propose a hybrid quantum architecture for engineering a photonicMott insulator-superfluid phase transition in a two-dimensional (2D) square lattice of a superconducting transmission line resonator (TLR) coupled to a single nitrogen-vacancy (NV) center encircled by a persistent current qubit. The localization-delocalization transition results from the interplay between the on-site repulsion and the nonlocal tunneling. The phase boundary in the case of photon hopping with real-valued and complex-valued amplitudes can be obtained using the mean-field approach. Also, the quantum jump technique is employed to describe the phase diagram when the dissipative effects are considered. The unique feature of our architecture is the good tunability of effective on-site repulsion and photon-hopping rate, and the local statistical property of TLRs which can be analyzed readily using presentmicrowave techniques. Our work opens new perspectives in quantum simulation of condensed-matter and many-body physics using a hybrid spin circuit-QED system. The experimental challenges are realizable using currently available technologies.