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Charge transport by way of objects that jiggle is a curious phenomenon. Here we present experiments on an electromechanical charge shuttle that reveal interesting electronic transport properties and rich dynamics. The current-voltage characteristics display distinctive jumps and hysteresis which reflect the influence of the vibrational environment on shuttle dynamics. These results provide fundamental guidance toward the understanding of transport phenomena in future electromechanical nanosystems and engineered microdevices.

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We consider the interference of two overlapping ideal Bose-Einstein condensates. The usual description of this phenomenon involves the introduction of a so-called condensate wave functions having a definite phase. We investigate the origin of this phase and the theoretical basis of treating interference. It is possible to construct a phase state, for which the particle number is uncertain, but phase is known. However, how one would prepare such a state before an experiment is not obvious.We show that a phase can also arise from experiments using condensates in Fock states, that is, having known particle numbers. Analysis of measurements in such states also gives us a prescription for preparing phase states. The connection of this procedure to questions of "spontaneously broken gauge symmetry" and to "hidden variables" is mentioned.