Electrically injected cavity polaritons

TL;DR

This paper demonstrates an electrically driven semiconductor device that produces cavity polaritons in the mid-infrared range, showing room-temperature polariton formation and selective electron injection into polariton states.

Contribution

It introduces a novel electrically injected cavity polariton device based on a quantum cascade structure embedded in a microcavity, operating at room temperature.

Findings

Room-temperature polariton anticrossing observed.

Electrons can be selectively injected into polariton states.

Device emits electroluminescence in the strong coupling regime.

Abstract

We have realised a semiconductor quantum structure that produces electroluminescence while operating in the light-matter strong coupling regime. The mid-infrared light emitting device is composed of a quantum cascade structure embedded in a planar microcavity, based on the GaAs/AlGaAs material system. At zero bias, the structure is characterised using reflectivity measurements which show, up to room temperature, a wide polariton anticrossing between an intersubband transition and the resonant cavity photon mode. Under electrical injection the spectral features of the emitted light change drastically, as electrons are resonantly injected in a reduced part of the polariton branches. Our experiment demonstrates that electrons can be selectively injected into polariton states up to room temperature.