Article

# Trapping single electrons on liquid helium

• ##### M. J. Lea
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.

0 Bookmarks
·
72 Views
• Source
##### Article: Jaynes-Cummings Models with trapped electrons on liquid Helium
[Hide abstract]
ABSTRACT: Jaynes-Cummings model is a typical model in quantum optics and has been realized with various physical systems (e.g, cavity QED, trapped ions, and circuit QED etc..) of two-level atoms interacting with quantized bosonic fields. Here, we propose a new implementation of this model by using a single classical laser beam to drive an electron floating on liquid Helium. Two lowest levels of the {\it vertical} motion of the electron acts as a two-level "atom", and the quantized vibration of the electron along one of the {\it parallel} directions, e.g., $x$-direction, serves the bosonic mode. These two degrees of freedom of the trapped electron can be coupled together by using a classical laser field. If the frequencies of the applied laser fields are properly set, the desirable Jaynes-Cummings models could be effectively realized.
Physical Review A 09/2009; 80. · 3.04 Impact Factor
• ##### Article: The structure of planar Coulomb crystals in RF traps
[Hide abstract]
ABSTRACT: We investigate the structure of one-component and multicomponent planar Coulomb crystals in RF traps. Due to the RF confinement particular features emerge, especially in the case of multicomponent crystals. After briefly discussing one-component planar crystals, we consider the case of multicomponent crystals and, in particular, planar bicrystals. We show that in the multicomponent case, the spatial separation among components depends on the strength of axial confinement which also imposes a limit on the number of ions that can exist in the innermost shell. These theoretical results are confirmed by molecular dynamics simulations. Finally, we discuss some experimental issues.
Journal of Physics B Atomic Molecular and Optical Physics 07/2009; 42(15):154004. · 2.03 Impact Factor
• Source
##### Article: Addition spectra of Wigner islands of electrons on superfluid helium
[Hide abstract]
ABSTRACT: We present here an experimental study of Wigner islands formed by electrons floating over helium. Electrons are trapped electrostatically in a mesoscopic structure covered with a helium film, behaving as a quantum dot in the near-classical limit. By removing electrons one by one, we are able to find the addition spectrum, i.e., the energy required to add (or extract) one electron from the trap with occupation number N . Experimental addition spectra are compared with Monte Carlo simulations for the actual trap geometry, confirming the ordered state of electrons over helium in the island.
Physical review. B, Condensed matter 01/2009; · 3.77 Impact Factor