Ultra-small Mode Volume Polariton Condensation via Precision $He^+$ Ion Implantation

TL;DR

This paper introduces a precise ion implantation technique to create ultra-small potential traps in GaAs microcavities, enabling single polariton condensate formation with high spatial resolution and strong coupling.

Contribution

The authors develop a novel focused $He^{+}$ implantation method to engineer micron-scale potential landscapes in GaAs microcavities, supporting polariton condensation in extremely small mode volumes.

Findings

Achieved potential traps with size ≤ 1.2 μm and mode volume ≈ 0.6 μm³.

Maintained strong coupling after ion implantation.

Enabled lithographic patterning with < 300 nm resolution.

Abstract

We present a novel method for generating potential landscapes in GaAs microcavities through focused $He^{+}$ implantation. The ion beam imprints micron-scale patterns of non-radiative centers that deplete the exciton reservoir and form a loss-defined potential minimum. Under non-resonant pumping, the resulting traps have a lateral size $\le 1.2 ~\mathrm{\mu m}$ and a three-dimensional mode volume of only $\approx 0.6 ~ \mathrm{\mu m^3}$, small enough to to support a single polariton condensate mode. The implantation process maintains strong coupling and provides lithographic ($ < 300 ~ \mathrm{nm}$) resolution. These loss-engineered traps effectively overcome the micrometer-scale limitations of conventional microcavity patterning techniques, opening new avenues for device development and polariton research within the quantum regime.