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Theory of coherent acoustic phonons in InGaN/GaN multi-quantum wells

G. D. Sanders·C. J. Stanton·Chang-Sub Kim
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Abstract

A microscopic theory for the generation and propagation of coherent LA phonons in pseudomorphically strained wurzite (0001) InGaN/GaN multi-quantum well (MQW) p-i-n diodes is presented. The generation of coherent LA phonons is driven by photoexcitation of electron-hole pairs by an ultrafast Gaussian pump laser and is treated theoretically using the density matrix formalism. We use realistic wurzite bandstructures taking valence-band mixing and strain-induced piezo- electric fields into account. In addition, the many-body Coulomb ineraction is treated in the screened time-dependent Hartree-Fock approximation. We find that under typical experimental conditions, our microscopic theory can be simplified and mapped onto a loaded string problem which can be easily solved.

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G. D. Sanders, C. J. Stanton, Chang-Sub Kim. 2002-06-11. Theory of coherent acoustic phonons in InGaN/GaN multi-quantum wells. https://doi.org/10.1103/physrevb.64.235316

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