Location of Repository

Interpretation of quantum jump and diffusion-processes illustrated on the Bloch sphere

By H. M. Wiseman and G. J. Milburn

Abstract

It is shown that the evolution of an open quantum system whose density operator obeys a Markovian master equation can in some cases be meaningfully described in terms of stochastic Schrödinger equations (SSE’s) for its state vector. A necessary condition for this is that the information carried away from the system by the bath (source of the irreversibility) be recoverable. The primary field of application is quantum optics, where the bath consists of the continuum of electromagnetic modes. The information lost from the system can be recovered using a perfect photodetector. The state of the system conditioned on the photodetections undergoes stochastic quantum jumps. Alternative measurement schemes on the outgoing light (homodyne and heterodyne detection) are shown to give rise to SSE’s with diffusive terms. These three detection schemes are illustrated on a simple quantum system, the two-level atom, giving new perspectives on the interpretation of measurement results. The reality of these and other stochastic processes for state vectors is discussed

Topics: Resonance fluorescence, Spectrum, Atom, 3100 Physics and Astronomy, 3107 Atomic and Molecular Physics, and Optics
Publisher: American Physical Society
Year: 1993
OAI identifier: oai:espace.library.uq.edu.au:UQ:247758

Suggested articles

Preview


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.