Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 1, 2005 | public
Journal Article Open

Quantum projection filter for a highly nonlinear model in cavity QED


Both in classical and quantum stochastic control theory a major role is played by the filtering equation, which recursively updates the information state of the system under observation. Unfortunately, the theory is plagued by infinite dimensionality of the information state which severely limits its practical applicability, except in a few select cases (e.g. the linear Gaussian case). One solution proposed in classical filtering theory is that of the projection filter. In this scheme, the filter is constrained to evolve in a finite-dimensional family of densities through orthogonal projection on the tangent space with respect to the Fisher metric. Here we apply this approach to the simple but highly nonlinear quantum model of optical phase bistability of a strongly coupled two-level atom in an optical cavity. We observe near-optimal performance of the quantum projection filter, demonstrating the utility of such an approach.

Additional Information

Copyright © 2005 Institute of Physics Received 13 March 2005, accepted for publication 29 April 2005, Published 14 September 2005, Print publication: Issue 10 (October 2005) The authors thank Mike Armen for useful discussions. This work was supported by the ARO (DAAD19-03-1-0073).


Files (984.6 kB)
Name Size Download all
984.6 kB Preview Download

Additional details

August 22, 2023
October 13, 2023