JOSEP INGLA AYNÉS
Our recent work on transverse electron focusing has just been published in Nano Letters. By patterning multiple quantum point contacts in a ballistic bilayer graphene device, we inject and collect electron jets which are reflected specularly up to seven times along the gate-defined edge of the sample.
The experiment is illustrated by the figure above, where the contacts are brown and the gates are dark yellow. The quantum point contacts are defined between the 50-nm-separated gates and, the electron jet trajectories are shown schematically by semi-circular arcs. The measured signal is shown in the right panel where voltage peaks associated with 0, 1, and 6 edge reflections are highlighted by arrows.
Since specularly reflected electrons are expected to preserve the valley pseudospin of the electrons, our work opens the way for new ballistic experiments which explicitly address this unique degree of freedom of the electrons.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme Marie Sklodowska Curie grant agreement no 101027187.