Temperature-independent current deficit due to induced quantum nanowire vibrations

We consider electronic transport through a suspended voltage-biased nanowire subject to an external magnetic field. In this paper, we show that the transverse magnetic field, which acts to induce coupling between the tunneling current and the vibrational modes of the wire, controls the current-voltage characteristics of the system in novel ways. In particular, we derive the quantum master equation for the reduced density matrix describing the nanowire vibrations. From this we find a temperature- and bias voltage-independent current deficit in the limit of high bias voltage since the current through the device is lower than its value at zero magnetic field. We also find that the corrections to the current from the back-action of the vibrating wire decay exponentially in the limit of high voltage. Furthermore, it is shown that the expression for the temperature- and bias voltage-independent current deficit holds even if the nanowire vibrational modes have been driven out of thermal equilibrium.