  Electrons floating on the surface of liquid helium are possible spin-qubits
for quantum information processing. Varying electric potentials are not
expected to modify spin states, which allows their transport on helium using a
charge-coupled device (CCD)-like array of underlying gates. This approach
depends upon efficient inter-gate transfer of individual electrons.
Measurements are presented here of the charge transfer efficiency (CTE) of few
electrons clocked back and forth above a short microscopic CCD-like structure.
A charge transfer efficiency of 0.99999992 is obtained for a clocking frequency
of 800 kHz.
