Piezoplasmonics: strain-induced tunability of plasmon resonance in AlAs quantum wells

TL;DR

This paper demonstrates how applying in-plane uniaxial strain to AlAs quantum wells can tune the 2D plasmon spectrum by redistributing charge carriers between valleys, revealing a new piezoplasmonic effect useful for studying band structures.

Contribution

The study introduces the piezoplasmonic effect in AlAs quantum wells, enabling strain-based tuning of plasmon resonance and measurement of inter-valley energy splitting.

Findings

Strain causes significant changes in the plasmon spectrum.

The inter-valley energy splitting depends on deformation.

Deformation potential of AlAs is measured as 5.6 eV.

Abstract

We demonstrate tuning of two-dimensional (2D) plasmon spectrum in modulation-doped AlAs quantum wells via the application of in-plane uniaxial strain. We show that dramatic change in the plasma spectrum is caused by strain-induced redistribution of charge carriers between anisotropic $X_x$ and $X_y$ valleys. Discovered piezoplasmonic effect provides a tool to study the band structure of 2D systems. We use piezoplasmonic effect to measure how the inter-valley energy splitting depends on the deformation. This dependency yields the AlAs deformation potential of $E_2 = (5.6 \pm 0.3)$~eV.