Strong coupling in semiconductor hyperbolic metamaterials

TL;DR

This paper demonstrates strong coupling between volume plasmon polariton modes in semiconductor hyperbolic metamaterials and quantum well intersubband transitions, leading to polariton formation in the infrared range.

Contribution

It provides the first experimental evidence of strong coupling in semiconductor HMMs with embedded quantum wells, enabling new infrared optoelectronic devices.

Findings

Observation of anticrossings in dispersion curves

Formation of upper and lower polariton branches

Demonstration of strong coupling in multiple VPP modes

Abstract

Semiconductor-based layered hyperbolic metamaterials (HMMs) house high-wavevector volume plasmon polariton (VPP) modes in the infrared spectral range. VPP modes have successfully been exploited in the weak-coupling regime through the enhanced Purcell effect. In this paper, we experimentally demonstrate strong coupling between the VPP modes in a semiconductor HMM and the intersubband transition of epitaxially-embedded quantum wells. We observe clear anticrossings in the dispersion curves for the zeroth-, first-, second-, and third-order VPP modes, resulting in upper and lower polariton branches for each mode. This demonstration sets the stage for the creation of novel infrared optoelectronic structures combining HMMs with embedded epitaxial emitter or detector structures.