The compound semiconductor gallium arsenide (GaAs) provides an ultra-clean platform for storing and manipulating quantum information, encoded in the charge or spin states of electrons confined in nanostructures. The absence of inversion symmetry in the zinc-blende crystal structure of GaAs however, results in strong piezoelectric coupling between lattice acoustic phonons and electrons, a potential hindrance for quantum computing architectures that can be charge-sensitive during certain operations. Here we examine phonon generation in a GaAs double dot, configured as a single- or two-electron charge qubit, and driven by the application of microwaves via surface gates. In a process that is a microwave analog of the Raman effect, stimulated phonon emission is shown to produce population inversion of a two-level system and provides spectroscopic signatures of the phononic environment created by the nanoscale device geometry.
@article{arxiv.1305.5982,
title = {Stimulated Phonon Emission in a Driven Double Quantum Dot},
author = {J. I. Colless and X. G. Croot and T. M. Stace and A. C. Doherty and S. D. Barrett and H. Lu and A. C. Gossard and D. J. Reilly},
journal= {arXiv preprint arXiv:1305.5982},
year = {2015}
}