QUANTUM MANIPULATIONS OF SMALL JOSEPHSON-JUNCTIONS

Low-capacitance Josephson junction arrays in the parameter range where single charges can be controlled are suggested as possible physical r ealizations of the elements which have been considered in the context of quantum computers. We discuss single and multiple quantum-bit syste ms. The systems an controlled by applied gate voltages, which also all ow the necessary manipulation of the quantum states. We estimate that the phase-coherence time is sufficiently long for experimental demonst ration of the principles of quantum computation.