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

We demonstrate tuning of a two-dimensional (2D) plasmon spectrum in modulation-doped AlAs quantum wells via the application of in-plane uniaxial strain. We show that the dramatic change in the plasma spectrum is caused by strain-induced redistribution of charge carriers between anisotropic Xx and Xy valleys. The discovered piezoplasmonic effect provides a tool to study the band structure of 2D systems. We use the 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 ± 0.3 ) eV.