Quantum phase transition of light in a 1-D photon-hopping-controllable resonator array

TL;DR

This paper proposes an experimental scheme to observe and control the insulator-superfluid transition of light in a 1-D array of superconducting resonators, enabling systematic study of quantum phase transitions.

Contribution

It introduces a tunable architecture for the insulator-superfluid transition of light, allowing independent control of interactions and hopping rates in a 1-D resonator array.

Findings

The scheme allows systematic exploration of quantum phase transitions in light.

High-efficiency measurement of photon statistics in each resonator.

Analysis indicates feasibility for small-scale experimental realization.

Abstract

We give a concrete experimental scheme for engineering the insulator-superfluid transition of light in a one-dimensional (1-D) array of coupled superconducting stripline resonators. In our proposed architecture, the on-site interaction and the photon hopping rate can be tuned independently by adjusting the transition frequencies of the charge qubits inside the resonators and at the resonator junctions, respectively, which permits us to systematically study the quantum phase transition of light in a complete parameter space. By combining the techniques of photon-number-dependent qubit transition and fast read-out of the qubit state using a separate low-Q resonator mode, the statistical property of the excitations in each resonator can be obtained with a high efficiency. An analysis of the various decoherence sources and disorders shows that our scheme can serve as a guide to coming experiments involving a small number of coupled resonators.