title: Pure Gaussian state generation via dissipation: a quantum stochastic differential equation approach.
abstract: Recently, the complete characterization of a general Gaussian dissipative system having a unique pure steady state was obtained. This result provides a clear guideline for engineering an environment such that the dissipative system has a desired pure steady state such as a cluster state. In this paper, we describe the system in terms of a quantum stochastic differential equation (QSDE) so that the environment channels can be explicitly dealt with. Then, a physical meaning of that characterization, which cannot be seen without the QSDE representation, is clarified; more specifically, the nullifier dynamics of any Gaussian system generating a unique pure steady state is passive. In addition, again based on the QSDE framework, we provide a general and practical method to implement a desired dissipative Gaussian system, which has a structure of quantum state transfer.
authors.affiliation: Department of Applied Physics and Physico-Informatics, Keio University, Hiyoshi, Kohoku, Yokohama, Japan. yamamoto@appi.keio.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto