Location: Room E, TNW building
Time: 16:00 hrs

abstract

A nanomechanical oscillator can serve as a universal coupling device interfacing atoms, optical photons and electrical circuits. I will report optical cooling with a crystalline semiconductor membrane via a new mechanism, in which the cooling force arises from the interaction between the photo-induced electron-hole pairs and the mechanical modes through the deformation potential coupling [1]. The optoelectronic mechanism is so efficient as to cool a mode down to 4K from room temperature with just 50 microwatts of light and a cavity with a finesse of 10 consisting of a standard mirror and the sub-wavelength-thick semiconductor membrane itself.  In a separate development we investigate the possibility to strongly couple the mechanical motion of a Si:N nano-membrane to the charge-flux degrees of freedom of a LC circuit where the membrane is electrically coupled to the capacitor of the circuit [2]. Theoretical analysis suggests that optical cooling of the resonant mode of the LC by several orders of magnitude via such an interface is possible. Together with a way to entangle atomic spin-polarized ensembles with nanomechanical oscillators [3], these functionalities allow for creating multi-facet quantum interfaces for metrology and quantum information processing.