Cooling a nanomechanical resonator by a triple quantum dot
Department of Physics and State Key Laboratory of Surface Physics, Fudan University - Shanghai 200433, China
2 Department of Applied Physics, Hong Kong Polytechnic University - Hung Hom, Hong Kong, China
Accepted: 7 July 2011
We propose an approach for achieving ground-state cooling of a nanomechanical resonator (NAMR) capacitively coupled to a triple quantum dot (TQD). This TQD is an electronic analog of a three-level atom in Λ configuration which allows an electron to enter it via lower-energy states and to exit only from a higher-energy state. By tuning the degeneracy of the two lower-energy states in the TQD, an electron can be trapped in a dark state caused by destructive quantum interference between the two tunneling pathways to the higher-energy state. Therefore, ground-state cooling of an NAMR can be achieved when electrons absorb readily and repeatedly energy quanta from the NAMR for excitations.
PACS: 03.65.Ta – Foundations of quantum mechanics; measurement theory / 42.50.Gy – Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption / 73.21.La – Quantum dots
© EPLA, 2011