Distance education as an object of study and reflection of pedagogy in Poland

The digitization of the media, their software and hardware combination of computers and the development of networks and their dissemination have made distance learning the subject of research, implementation of practical and scientific reflection once again. Those actions are promoted not only by the development of ICT, but also by progressive globalization, demographic changes and economic and cultural challenges. The scientific discourse is also a part of Polish experiences.The previous treatment of the subject of this paper were historical in nature, fragmentary or were descriptions of individual experiments and experiences of individual universities. Presented approach has not only a synthetic character, but also provides an outline of the original, the Polish concept of teaching – blended learning

A continuum individual based model of fragmentation: dynamics of correlation functions

An individual-based model of an infinite system of point particles in Rd is proposed and studied. In this model, each particle at random produces a finite number of new particles and disappears afterwards. The phase space for this model is the set Γ of all locally finite subsets of Rd. The system's states are probability measures on  Γ the Markov evolution of which is described in terms of their  correlation functions in a scale of Banach spaces. The existence and uniqueness of solutions of the corresponding evolution equation are proved

Dark periods and revivals of entanglement in a two qubit system

In a recent paper Yu and Eberly [Phys. Rev. Lett. {\bf 93}, 140404 (2004)] have shown that two initially entangled and afterwards not interacting qubits can become completely disentangled in a finite time. We study transient entanglement between two qubits coupled collectively to a multimode vacuum field and find an unusual feature that the irreversible spontaneous decay can lead to a revival of the entanglement that has already been destroyed. The results show that this feature is independent of the coherent dipole-dipole interaction between the atoms but it depends critically on whether or not the collective damping is present. We show that the ability of the system to revival entanglement via spontaneous emission relies on the presence of very different timescales for the evolution of the populations of the collective states and coherence between them.Comment: 4 pages, 3 figure

High-fidelity atomic-state teleportation protocol with non-maximally-entangled states

We propose a protocol of the long-distance atomic state teleportation via cavity decay, which allows for high-fidelity teleportation even with currently available optical cavities. The protocol is based on the scheme proposed by Bose \emph{et al.} [Phys. Rev. Lett. {\textbf{83}}, 5158 (1999)] but with one important modification: it employs non-maximally-entangled states instead of maximally entangled states.Comment: 8 pages, 6 figures, accepted for publication in Phys. Rev.

Effective generation of cat and kitten states

We present an effective method of coherent state superposition (cat state) generation using single trapped ion in a Paul trap. The method is experimentally feasible for coherent states with amplitude $\alpha \le 2$ using available technology. It works both in and beyond the Lamb-Dicke regime.Comment: 11 pages, 8 figure