Frequency Conversion: Side-band cooling, state-swapping, and coherent control of mechanical resonators
Sideband cooling is a technique that potentially allows mechanical resonators to be prepared in their ground states, important for future applications in quantum technologies. Tian has recently shown that side-band cooling can be implemented by modulating the coupling between a nano-resonator and a superconducting oscillator, a process of frequency conversion [L. Tian, PRB 79, 193407 (2009)]. While side-band cooling is usually treated in the steady-state regime, the effective resonant coupling will also generate near perfect state-swapping from the superconductor to the mechanical resonator. We perform numerical simulations of this system, examining the ground-state cooling achieved by the state-swapping. Further, we show that the superconducting oscillator can be used to control the amplitude and phase of the resonator, while simultaneously cooling it, and thus act as a coherent "quantum feedback controller".
- Pub Date:
- March 2010
- Quantum Physics;
- Condensed Matter - Mesoscale and Nanoscale Physics
- revtex4-1, 4 pages, 1 png figure. v3: further results on coherent feedback control