Mercredi 15 octobre 2014 à 10h15
Salle 234, Ecole de Physique

Time-bin single electron qubits (multiple peak electrons)

Michael Moskalets, Kharkiv Polytechnic Institute, Ukraine

I discuss a few proposals how to create electrons with multiple peak profiles, which are natural implementation of time-bin qubits for coherent electronic circuits. In contrast to its photonic counterpart an electron in solid state resides not in vacuum but on the surface of the Fermi sea. This fact has an interesting and somehow unexpected consequence. Namely, a multiple-peak electron can host a piece of the Fermi sea with a variable phase different from the ambient Fermi sea. This inclusion plays a role of the phase carrier, whose presence is easily detected via an interferometric measurement: The visibility as a function of an interferometer imbalance shows a pronounced plateau whose value depends on the phase difference. The phase carrier is electrically neutral but consists of electron-hole pairs, which are separated by an imbalanced interferometer. Interestingly, the resulting DC current is produced not by the whole phase carrier but by its part, which interferes with the reference Fermi sea. Another interesting feature is that the creation of a phase carrier does not require an extra energy compared to the one necessary for creation of a single-electron itself.