arXiv subjects
Publications and source records attributed to Mikalai Karelin.
An entanglement measure for pure-state continuous-variable bi-partite problem, the Schmidt number, is analytically calculated for one simple model of atom-field scattering.
Model of partially coherent pulses, based on the concept of "hidden coherence", introduced recently by Picozzi and Haelterman in framework of parametric wave mixing, is presented. The nonuiform and nonstationary phase shift, while completely deterministic, results in the beam properties, which are typical for partially coherent light - low contrast of interference effects, increase of spectral width and so on - i. e. light becomes effectively non-coherent. The proposed model is studied in framework of coherent mode decomposition, its main properties and limitations of the model are discussed.
Uncertainty relations for mixed quantum states (precisely, purity-bounded position-momentum relations, developed by Bastiaans and then by Man'ko and Dodonov) are studied in general multi-dimensional case. An expression for family of mixed states at the lower bound of uncertainty relation is obtained. It is shown, that in case of entropy-bounded uncertainty relations, lower-bound state is thermal, and a transition from one-dimensional problem to multi-dimensional one is trivial. Results of numerical calculation of the relation lower bound for different types of generalized purity are presented. Analytical expressions for general purity-bounded relations for highly mixed states are obtained.