An Electronic Array On Liquid Helium

Surface‐state electrons on liquid helium, have been proposed as condensed matter qubits. We have demonstrated that small numbers of electrons, including a single isolated electron, can be held in an electrostatic trap above the surface of superfluid helium and individually detected using a superconducting single‐electron transistor (SET). A new design for a quantum information processor, using an array of electron traps on liquid helium, has been fabricated on a Si wafer using a superconducting A1 SET.