CQuIC Seminars
Resolved Sideband Emission of Quantum Dots Strained by Surface Acoustic Waves
Presented by Stephen M. Carr, Sandia National Laboratory, Albuquerque, NM
Remarkable and relentless progress has recently been realized in the pursuit of the cooling of mesoscopic mechanical systems toward the quantum ground state. For certain optomechanical and electromechanical cooling schemes, a key technical requirement is the attainment of the resolved sideband regime, where the mesoscopic mechanical mode frequency exceeds the linewidth of the central resonance. A particularly intriguing theoretical proposal [1] is based on resonant laser excitation of a phonon sideband of a quantum dot embedded in a mesoscopic mechanical resonator. In this seminar I will describe my previous experimental work, performed at the National Institute of Standards and Technology (NIST), on self-assembled quantum dots strained by surface acoustic waves, which was motivated in part by the aforementioned theoretical proposal [1]. A cryogenic experimental apparatus was designed, constructed, and implemented to enable precision optical measurements and radio-frequency electrical transmission to a semiconductor chip at low temperature. Surface acoustic waves in the GHz range were generated on-chip using nanofabricated interdigital transducers, resulting in the controlled inducement of phonon sidebands in the quantum dot emission spectrum. The resolved sideband regime and optical frequency conversion were experimentally demonstrated [2] using resonant spectroscopy. Finally, I will briefly describe my current work at Sandia National Laboratory on the experimental investigation of adiabatic and non-adiabatic qubit evolution and encoding using semiconductor devices, including electrostatically-defined quantum dots. [1] Physical Review Letters 92, 075507 (2004). [2] Physical Review Letters 105, 037401 (2010).
3:30 pm, Thursday, May 10, 2012
PAIS-2540, PAIS
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