Condensed Matter Physics Seminar

Spin transport and manipulation in moving quantum dots

Dr. James Stotz
Queen's University Physics

Time
Wed. October 18, 2006     10:30 AM     Stirling 501

Abstract

To realize quantum information processing schemes in semiconductor systems, the coherent transport of spin carriers is of significant importance. Recent work using the unique system of dynamic quantum dots (DQDs) shows that small ensembles of electron spins can be transported over long distances and manipulated while retaining their microscopic confinement. The DQDs are produced by the superposition of piezoelectric potentials from surface acoustic wave beams propagating along orthogonal directions on a GaAs/(Al,Ga)As (001) quantum well sample. While it is clear that the confinement potential of the DQDs reduces D'yakonov-Perel' spin dephasing during transport, the effects of the strain and magnetic fields on spin dephasing are much more complicated. We will discuss the underlying mechanisms behind the ability to transport spins over long distances including the impact of confinement on spin coherence. In addition, the strong dephasing of the spin coherence in an external magnetic field will be addressed, and the influence of the acoustic strain field on the transport will be introduced.

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