Professor Xuedong Hu
DEPARTMENT OF PHYSICS
SUNY at Buffalo

Realizing singlet-triplet qubits in multivalley Si quantum dots

Spins in semiconductor nanostructures are promising qubit candidates for a solid state quantum computer, and have seen some truly impressive experimental progresses in the past few years. In this talk I will report some recent calculations where we explore the consequences of multiple conduction band valleys in the coherent manipulation of spin states in a Si double quantum dot. We examine specifically the feasibility in a Si double dot the pulsed manipulation experiments done in GaAs [1]. In addition to identifying the conditions under which a Si double dot behaves similarly to a GaAs double dot, we show that such pulsed experiments, together with sweeping of applied magnetic field, can help determine the valley splitting in a Si double dot.

[1] J.R. Petta et al., Science 309, 2180 (2005).