Classical and quantum dynamics of indirect excitons driven by surface acoustic waves

We perform explicit time-dependent classical and quantum propagation of a spatially indirect exciton (SIX)
driven by surface acoustic waves (SAWs) in a semiconductor heterostructure device.We model the SIX dynamics
at different levels of description, from the Euler-Lagrange propagation of structureless classical particles to
unitary Schrödinger propagation of an electron-hole wave packet in a mean field and to the full quantum
propagation of the two-particle complex. A recently proposed beyond mean-field self-energy approach, adding
internal virtual transitions to the c.m. dynamics, has been generalized to time-dependent potentials and turns out
to describe very well full quantum calculations, while being orders of magnitude numerically less demanding.
We show that SAW-driven SIXs are a sensitive probe of scattering potentials in the devices originating, for
example, from single impurities or metallic gates, due to competing length and energy scales between the SAW
elastic potential, the scattering potential, and the internal electron-hole dynamic of the SIX. Comparison between
different approximations allow us to show that internal correlation of the electron-hole pair is crucial in scattering
from shallow impurities, where tunneling plays a major role. On the other hand, scattering from broad potentials,
i.e., with length scales exceeding the SIX Bohr radius, is well described as the classical dynamics of a pointlike
SIX. Recent experiments are discussed in light of our calculations