SPECIAL Laboratory for Physical Sciences Seminar Announcement
THURSDAY, October 21, 2010; 11 am
Seminar Room, Lower Level, LPS
8050 Greenmead Dr., College Park, MD 20740 301-935-6400
Title: Single-spin state monitoring by measurement of three complementary observables
Rusko Ruskov
Laboratory for Physical Sciences
Abstract:
We consider the evolution of a qubit (spin 1/2) under the simultaneous continuous measurement of three noncommuting qubit operators \sigma_x, \sigma_y, and \sigma_z. For identical ideal detectors, the qubit state evolves
by approaching a pure state with a random direction in the Bloch vector space and by undergoing locally isotropic diffusion in the perpendicular directions. The quantum state conditioned on the complete detector record is used to assess the fidelity of classically inspired estimates based on running time averages and discrete time bin detector outputs.