We develop a coherent beam splitter for single electrons driven through two tunnel-coupled quantum wires by surface acoustic waves (SAWs). The output current through each wire oscillates with gate voltages to tune the tunnel-coupling and potential difference between the wires. This oscillation is assigned to coherent electron tunneling motion that can be used to encode a flying qubit and is well reproduced by numerical calculations of time evolution of the SAW-driven single electrons. The oscillation visibility is currently limited to about 3%, but robust against decoherence, indicating that the SAW-electron can serve as a novel platform for a solid-state flying qubit.
@article{arxiv.2004.11553,
title = {Coherent beam splitting of flying electrons driven by a surface acoustic wave},
author = {R. Ito and S. Takada and A. Ludwig and A. D. Wieck and S. Tarucha and M. Yamamoto},
journal= {arXiv preprint arXiv:2004.11553},
year = {2021}
}