Quantum Transport of Excitons in Nano-Devices

An indirect exciton is a bound pair of an electron and a hole in spatially separated layers. Such bosonic particles can be created optically in semiconductor double quantum wells or layered two-dimensional materials. Indirect excitons couple to external electric field via their permanent dipole moment. This allows one to engineer arbitrary potential landscapes for the excitons. We study theoretically the problem of quantum transport of indirect excitons through constrictions, including quantum-point contacts. We show that this problem provides a novel counterpart to previous investigations of electron transport in nano-devices. We calculate analytically and numerically the conductance and the real-space current density of excitons propagating through single, double, and multiple slits. Our calculations illustrate that hallmark ballistic quantum transport phenomena, such as diffraction, interference, and the Talbot effect, are experimentally observable with excitons by spatially resolved photoluminescence imaging.