1210.2632 (Naoki Yamamoto)

Decoherence-free linear quantum systems    [PDF]

Naoki Yamamoto

This paper provides a general theory to characterize and construct a decoherence-free (DF) dynamics for infinite dimensional (i.e., continuous-variable) linear open quantum systems. The main idea is that, based on the Heisenberg picture of the dynamics rather than the commonly-taken Schrodinger picture, the notion of controllability and observability in control theory is employed to characterize a DF dynamics. A particularly useful result is a general if and only if condition for a linear system to have a DF component; this condition is used to demonstrate how to actually construct a DF dynamics in some specific systems. It is also shown that, as in the finite dimensional (i.e., discrete-variable) case, we are able to do coherent manipulation and preservation of a state of a DF dynamics.

View original: http://arxiv.org/abs/1210.2632