Qubit state monitoring by measurement of three complementary observables
Quantum Physics
2010-09-20 v1 Statistical Mechanics
Abstract
We consider the evolution of a spin 1/2 (qubit) under the simultaneous continuous measurement of three non-commuting qubit operators sigma_x, sigma_y, 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.
Keywords
Cite
@article{arxiv.1006.2013,
title = {Qubit state monitoring by measurement of three complementary observables},
author = {Rusko Ruskov and Alexander N. Korotkov and Klaus Mølmer},
journal= {arXiv preprint arXiv:1006.2013},
year = {2010}
}
Comments
5 pages, 4 figures