Trapping single electrons on liquid helium

Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK; CEA, Saclay, France
Journal of Physics and Chemistry of Solids (Impact Factor: 1.53). 01/2005; DOI: 10.1016/j.jpcs.2005.05.052

ABSTRACT Surface-state electrons on liquid helium, localised in quantum dots, have been proposed as condensed matter qubits. We now demonstrate experimentally that small numbers of electrons, including a single isolated electron, can be held in a novel electrostatic trap above the surface of superfluid helium. A potential well is created using microfabricated electrodes in a 5 μm diameter pool of helium. Electrons are injected into the trap from an electron reservoir on a helium microchannel. They are individually detected using a superconducting single-electron transistor (SET) as an electrometer. A Coulomb staircase is observed as electrons leave the trap one-by-one until the trap is empty. A design for a prototype quantum information processor using an array of electron traps on liquid helium is presented.

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