Counting electrons on helium with a single electron transistor – Mike Lea
Date: Mon. October 27th, 2003, 12:30 pm-1:30 pmLocation: Rockefeller 221
Electrons on liquid helium have been proposed as qubits [1], using excited Rydberg states [2] as the |0> and |1> quantum states. This requires the trapping of single electrons in quantum wells, the excitation of Rydberg states using millimetric microwaves and the detection of the quantum states of the electrons. Progress towards these objectives will be described. In particular, we have detected individual trapped electrons on a pool of helium, 0.8 micron deep and 5 micron diameter, using a superconducting single-electron transistor (SET). Electrons on the helium surface induce a positive charge in the SET island and a phase shift in the Coulomb blockade oscillations (CBO) in the SET source-drain current. Individual electrons can be detected and counted as they enter and leave the pool [3]. The implications of these results for the development of electronic qubits on helium will be discussed.