Colliding Electrons and Holes in Semiconductors to Reconstruct Berry Curvature*

Electron-hole recollisions occur when a probe laser beam excites electron-hole pairs in a semiconductor that is driven by sufficiently strong THz-frequency electric fields [1]. The THz accelerates the electron-hole pairs and causes recollision, leading to the release of photons at higher energy than the probe in a process called high order sideband generation (HSG).

The intensity and polarization of each sideband depends on the relative polarizations of the probe and THz [2]. One cause of this dynamical birefringence is quantum interference between electron-hole recollision pathways under non-Abelian Berry curvature from the coupling between valence bands. In this talk I will present HSG experiments done in GaAs and demonstrate how to extract parameters relating to hole dynamics. This procedure opens the door to measurements of the complete electronic structure of semiconductors, including Berry curvature, Bloch wavefunctions, and effective Hamiltonian parameters.
References:
Zaks, B., et al., Nature, 483, 580-583 (2012); Zaks, B., et al., APL, 102, 012104 (2013); Banks, H., et al., PRL, 111, 267402 (2013)
Banks, H., et al., PRX, 7, 0401042 (2017)