89 research outputs found
Easy Monitored Entangled States
We discuss the generation and monitoring of durable atomic entangled state
via Raman-type process, which can be used in the quantum information
processing.Comment: 9 pages, 2 figures, the previous title "Durable Entanglement in
Atomic Systems" is replaced by new title, accepted to Appl. Phys. Let
Quantum phase via the angular momentum
Cataloged from PDF version of article.An approach to the quantum phase, taking into account the process of light generation and extending in this way the operational approach, is proposed. The cosine and sine operators of the phase difference of the two circularly polarized modes are determined with the aid of a polar decomposition of the angular momentum of radiative transition and conservation of the total angular momentum. Application of the approach to the Jaynes-Cummings model for an electric dipole transition shows consistency with the classical definition of the phase difference and with the results of standard operational approach as well
Quantification of entanglement via uncertainties
We show that entanglement of pure multi-party states can be quantified by
means of quantum uncertainties of certain basic observables through the use of
measure that has been initially proposed in [10] for bipartite systems.Comment: Changed content, references added 7 pages, no figures, PRA in pres
Steady state entanglement of two atoms created by classical driving field
The stabilization of steady state entanglement caused by action of a
classical driving field in the system of two-level atoms with the dipole
interaction accompanied by spontaneous emission is discussed. An exact solution
shows that the maximum amount of concurrence that can be achieved in Lamb-Dicke
limit is 0.43, which corresponds to the entanglement
ebit. Dependence of entanglement on interatomic distance and classical driving
field is examined numerically.Comment: 14 pages, 2 figure
Detecting squeezed phonons through an indirect radiative transition
Cataloged from PDF version of article.A model of the effect of the longitudinal optical phonon number distribution on the Rabi oscillations of the photons involved in the associated indirect transition in a semiconductor is presented. It is shown that a faster cavity photon revival rate is obtained given an initial squeezed thermal phonon state. This is the result of pairwise correlations of phonons due to squeezing and also holds true when phonons are in squeezed vacuum or in squeezed number states; It may be possible to use this effect to detect squeezing in phonons. (C) 1997 American Institute of Physics
Radiation phase and Stokes parameters
Cataloged from PDF version of article.The approach which has been proposed by one of us [Optics Comm. 136 (1997) 219] is developed. The quantum phase properties of radiation are determined via the conservation of the angular momentum in the interaction with a source. It is shown that the use of two dual representations of the angular momentum of the dipole transition leads to the definition of five operators similar in some sense to the Stokes operators of the radiation. The approach is compared with that by Pegg and Barnett [20]. (C) 1998 Elsevier Science B.V
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