Quantum-correlated photons from semiconductor cavity polaritons

TL;DR

This paper demonstrates that optically confined semiconductor cavity polaritons can produce quantum-correlated photons with antibunching, opening new avenues for quantum state generation and many-body quantum states of light.

Contribution

It shows that small mode volume confinement of polaritons induces strong nonlinearity, enabling antibunched photon emission and advancing the field of quantum polaritonics.

Findings

Achieved antibunching in photon emission from confined polaritons

Demonstrated weak blockade regime with small mode volume

Proved potential for scalable single-photon sources

Abstract

Over the past decade, exciton-polaritons in semiconductor microcavities have attracted a great deal of interest as a driven-dissipative quantum fluid. These systems offer themselves as a versatile platform for performing Hamiltonian simulations with light, as well as for experimentally realizing nontrivial out-of-equilibrium phase transitions. In addition, polaritons exhibit a sizeable mutual interaction strength that opens up a whole range of possibilities in the context of quantum state generation. While squeezed light emission from polaritons has been reported previously, the granular nature of polaritons has not been observed to date. The latter capability is particularly attractive for realizing strongly correlated many-body quantum states of light on scalable arrays of coupled cavities. Here we demonstrate that by optically confining polaritons to a very small effective mode volume, one can reach the weak blockade regime, in which the nonlinearity turns strong enough to become significant at the few particle level, and thus produce a non-negligible antibunching in the emitted photons statistics. Our results act as a door opener for accessing the newly emerging field of quantum polaritonics, and as a proof of principle that optically confined exciton-polaritons can be considered as a realistic, new strategy to generate single photons.