Bill Coish: Spin and Orbital Coherence in Quantum Dots for Quantum Information Processing

Monday, June 11, 2012 12:30 pm - 1:30 pm EDT (GMT -04:00)

Abstract

Semiconductor quantum dots provide a versatile and potentially scalable mechanism for manipulating quantum information encoded in discrete orbital and spin degrees of freedom. I will review the state-of-the-art in current developments in this field (leading to fast control on a scale of 200 picoseconds and very long memory times in excess of 200 microseconds). I will also point out the limitations of these developments and discuss two recent ideas to push the field toward high-fidelity scalable control: (1) Information encoded into hole (rather than electron)-spin degrees of freedom can be preserved and manipulated with much higher fidelity. In this context, I will briefly discuss our theory of single-hole spin echo dynamics, and (2) I will present our recent theory of quantum transport through a triple-quantum-dot molecule, accounting for high harmonics of Aharonov-Bohm interference. The results of this second study provide a mechanism for sensitive electric and magnetic field noise measurements and may provide an experimental test bed for dephasing-induced transport in biomolecules and quantum networks.