Quantum computing with electrons on helium

A concept for a quantum computer based on electrons localized above a helium film as quantum logic elements (qubits) is described. Each qubit is made of combinations of the ground and first excited state of an electron trapped in the image potential well at the surface. An array of electrodes beneath the surface restrict the lateral motion of electrons. Proposed mechanisms for one and two qubit logic operations and a simultaneous readout of the final state of all qubits are discussed. The principle decay channel for the excited state is via the emission of one phonon into the bulk liquid. Dephasing is estimated to be dominated by Johnson noise in the control electrodes. These times are on the order of View the MathML source and allow about 104 operations.