Long-Distance Charge Transport in a Single Electron Conveyor Device in (Al,Ga)As

For the realization of scalable quantum computing architectures enabling topological error correction, a transfer of the qubit information over distances of at least a few microns is required for making space for signal vias and allowing for tiling of qubit registers with classical control-circuits. Instead of coupling qubits by employing surface acoustic waves, we chose a one-dimensional, gate-defined conveyor belt-like device layout where electrons are moved between qubit sites by translating the potential minima in which the electrons are trapped. Here, the direction and the velocity of the electron transport are not limited by the crystal’s properties.

In this talk, I will present a device designed to allow the shuttling of electrons over 7 µm with only four voltage signals, whereby in principle arbitrary distances are feasible. We employed high-yield, multi-layer electron beam lithography in order to fabricate the required 100 metallic gates. I will show results on pumping charges from one reservoir to the other by filling each potential minimum in the conveyor with up to five electrons. We observed charge transport which is independent of a bias voltage and linear in frequency.