Semiconductor Membranes for Electrostatic Exciton Trapping in Optically Addressable Quantum Transport Devices

Combining the capabilities of gate-defined quantum transport devices in $\mathrm{Ga}\mathrm{As}$-based heterostructures and optically addressed self-assembled dots could open up broad perspectives technologies. For example, interfacing stationary solid-state qubits with photonic states would a pathway towards realization network extended processing capacity each node. While gated allow very flexible confinement electrons or holes, excitons without some element self-assembly is much harder. To address this limitation, we introduce technique to realize exciton traps wells via local electric fields by thinning heterostructure down 220-nm-thick membrane. We show that mobilities over $1\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{2}\phantom{\rule{0.2em}{0ex}}{\mathrm{V}}^{\ensuremath{-}1}\phantom{\rule{0.2em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$ can be retained point contacts Coulomb oscillations observed on structure, which implies does not compromise quality. Furthermore, lowering energy quantum-confined Stark effect confirmed, thus forming traps. These results lay technological foundations for like single-photon sources, spin-photon interfaces eventually nodes $\mathrm{Ga}\mathrm{As}$ wells, realized entirely top-down fabrication process.