Abstract
We study quantum trajectories of collective atomic spin states of effective two-level atoms driven with laser and cavity fields. We show that interesting “entangled-state cycles” arise probabilistically when the (Raman) transition rates between the two atomic levels are set equal. For odd (even) , there are possible cycles. During each cycle the -qubit state switches, with each cavity photon emission, between the states , where is a Dicke state in a rotated collective basis. The quantum number , which distinguishes the particular cycle, is determined by the photon counting record and varies randomly from one trajectory to the next. For even it is also possible, under the same conditions, to prepare probabilistically (but in steady state) the Dicke state , i.e., an -qubit state with excitations, which is of particular interest in the context of multipartite entanglement.
2 More- Received 28 June 2007
DOI:https://doi.org/10.1103/PhysRevA.77.033810
©2008 American Physical Society