Polariton-generated intensity squeezing in semiconductor micropillars.

The generation of squeezed and entangled light fields is a crucial ingredient for the implementation of quantum information protocols. In this context, semiconductor materials offer a strong potential for the implementation of on-chip devices operating at the quantum level. Here we demonstrate a novel source of continuous variable squeezed light in pillar-shaped semiconductor microcavities in the strong coupling regime. Degenerate polariton four-wave mixing is obtained by exciting the pillar at normal incidence. We observe a bistable behaviour and we demonstrate the generation of squeezing near the turning point of the bistability curve. The confined pillar geometry allows for a larger amount of squeezing than planar microcavities due to the discrete energy levels protected from excess noise. By analysing the noise of the emitted light, we obtain a measured intensity squeezing of 20.3%, inferred to be 35.8% after corrections.