1. A current-controlling device comprising: a first conductor and a second conductor; a tunneling barrier comprising a first insulation layer, the tunneling barrier electrically isolates the first conductor from the second conductor; at least one mobile charge positionable within the tunneling barrier; and a gate, wherein a voltage applied to the gate moves the mobile charge to a position between the first conductor and the second conductor within the tunneling barrier, thus deforming the shape of the energy barrier between the first conductor and the second conductor.