Manipulation of Individual Electronic Spins in Semiconductors

摘要

Manipulating individual spins in a solid, such as for quantum information processing or a spin-tronic device, requires the ability to quickly and coherently reorient a spin while leaving its neighbors unaffected. Using traditional electron spin resonance methods is problematic because of the difficulty of confining oscillating magnetic fields to small volumes. In contrast, g-tensor modulation resonance, which has been demonstrated in quantum wells, uses the electric field to exploit differences in the spin-orbit interaction in and around the confining structure and should be scalable. I will present theoretical calculations of g-tensor modulation resonance spin manipulation in quantum dots and donors and show that such schemes are feasible for manipulation of single spins. For InAs/GaAs quantum dots it is possible to rapidly reorient the spin in an arbitrary direction with only the application of a static magnetic field and the application of pulsed electric fields from a gate. Donors behave much like quantum dots, with the advantage that they do not suffer from variations in composition and size.