Surprises in quantum electromechanics
Université McGill, Montréal, Canada
Fri, Jun. 08th 2007, 11:00
NIMBE Bât 546, p.21, CEA-Saclay
(attention : jour et salle inhabituels / unusual room and day
séminaire exceptionnel en SALLE CAFE du SPEC)
A nano-electromechanical system consists of a micron-scale mechanical resonator coupled to a mesoscopic electronic conductor. The dissipative quantum mechanics of these systems is particularly interesting. How do the tunneling excitations in the conductor heat and damp the oscillator? To what extent do they act as an effective thermal bath? I will review recent theoretical work which demonstrates how a generic out-of-equilibrium mesoscopic conductor can act as an effective thermal bath. I will also discuss the interesting case where this bath is formed by out-of-equilibrium, incoherently-tunneling Cooper pairs. This system is remarkable in that significant cooling of the oscillator is possible; it can also exhibit a negative-damping instability reminiscent of a laser, characterized by strong feedback between the dynamics of the oscillator the tunneling of the Cooper pairs. Both these effects have recently been seen in experiment.