Photon-pair blockade in a Josephson-photonics circuit with two nondegenerate microwave resonators

TL;DR

This paper proposes a Josephson-photonics circuit that generates antibunched photon pairs in microwave resonators, offering a practical source for quantum technologies by exploiting charge qubit-induced anticorrelations.

Contribution

It introduces a novel circuit design utilizing a charge qubit and nondegenerate resonators to produce correlated photon pairs with antibunching properties.

Findings

Resonance condition enables photon-pair emission.

Anticorrelations inhibit simultaneous Cooper pair tunneling.

Potential for microwave quantum light sources.

Abstract

We propose to generate photon-pair blockade in a Josephson-photonics circuit that consists of a dc voltage-biased Josephson junction in series with a superconducting charge qubit and two nondegenerate microwave resonators. The two-level charge qubit is utilized to create anticorrelations of the charge transport; that is, the simultaneous Cooper pair tunneling events are inhibited. When the Josephson frequency matches the sum of resonance frequencies of the charge qubit and the two resonators, we demonstrate that the two resonators can release their energies in the form of antibunched pairs of two strongly correlated photons. The present work provides a practical way for producing a bright microwave source of antibunched photon pairs, with potential applications ranging from spectroscopy and metrology to quantum information processing.