Annalen der Physik

The center graph shows the tunable double-control quantum interference as the detuning frequencies vary. As the two-photon resonance occurs (i.e., δ_p- δ_c = 0 or δ_p- δ_c' = 0), the “double-control interference” parameter Δ drastically changes. Picture: J. Qi Shen, p. 85 in this issue. Background graph taken from C. Emary, C. Pöltl, T. Brandes, Phys. Rev. B 80, 235321 (2009) http://prb.aps.org/abstract/PRB/v80/i23/e235321, © 2009 by The American Physical Society).

There are solutions of Maxwell equations in vacuum in which the magnetic and the electric lines have a nontrivial topology. This behavior has physical consequences since it is related to classical expressions indicating aspects of the photon content of the electromagnetic field. In this work an exact solution of Maxwell equations in vacuum is presented, having non trivial topology, in which there is an exchange of helicity between the electric and magnetic part of such field.

A study of f(R)-gravity with torsion in the presence of the most general ELKO matter is presented, checking the consistency of the conservation laws with the matter field equations. In addition, some mathematical features of the field equations in connection with a cosmological application are discussed.

Multilevel quantum coherence and its quantum-vacuum counterpart are suggested in order to achieve new photonic and quantum optical applications. It is shown that a three-level dark state in a four-level tripod-configuration atomic system consists of three lower levels, where quantum interference between two control transitions arises. It is pointed out that the controllable optical response can be utilized to design some fascinating new photonic devices such as logic gates, photonic transistors and switches at quantum level.

The dynamics of a new Poincaré gauge theory of gravity model is investigated, which has cross coupling between the spin-0+ and spin-0-modes. To this end a homogeneous-isotropic cosmologies is considered which is relatively simple, and yet all the modes have non-trivial dynamics which reveals physically interesting and possibly observable results. More specifically, an isotropic Bianchi class A cosmologies has been investigated.

It is shown that in the trapped ion-laser interaction all the regimes may be considered analytically. This applies not only for different laser intensities, but also away from resonance and from the Lamb-Dicke regime. A dispersive Hamiltonian for the high intensity regime is found, that, being diagonal, allows for an easy calculation of the evolution operator.