A quantum dot pump coupled with a single quantum Hall edge channel

Development of single-electron sources is a crucial step towards a fermion version of quantum optics and a solid-state quantum processing. Further development of single-electron sources is desired, since existing sources do not cover the emission energy range of 1 – 60 meV. We theoretically and experimentally propose a new type of a single-electron source, which is composed of an interacting quantum dot and a single lead. As the quantum dot is coupled to the single lead (a chiral quantum Hall edge), electron-hole pairs are pumped by AC modulation of the quantum dot. The energy of pumped electrons can be 10 - 60 meV with help of the charging energy in the quantum dot while the hole energy is near the Fermi energy. Utilizing the energy separation, the electron and the hole of a pumped pair are spatially split by applying a tunable-potential barrier located on the path of the pumped pair. We theoretically describe the pumping mechanism using a master equation. We find that the single-electron generation resulting from the pumping and splitting of the electron-hole pairs is identified by characteristic triangular shape regions in the pump map. Our single-electron source is experimentally realized, and the obtained pump map is in good agreement with the theoretical result.