We detail the influence of a magnetic field on exciton-polaritons inside a semiconductor microcavity. Magnetic field can be used as a tuning parameter for exciton and photon resonances. We discuss the change of the exciton energy, the oscillator strength, and redistribution of the polariton density along the dispersion curves due to the magnetically induced detuning. We have observed that field-induced shrinkage of the exciton wave function has a direct influence not only on the exciton oscillator strength, which is observed to increase with the magnetic field, but also on the polariton linewidth. We discuss the effect of the Zeeman splitting on polaritons the magnitude of which changes with the exciton Hopfield coefficient and can be modeled by independent coupling of the two spin components of excitons with cavity photons.

A simple theory of the quantum interference in a loop structure due to Larmor precession of the electron spin is presented in this paper. A `spin ballistic regime' is assumed, where the phase-relaxation length for the spin part of the wave function (L(s)) is much greater than the relaxation length for the `orbital part' (L(e)). In the presence of an additional periodic magnetic field, the spin part of the electron's wave function acquires a phase shift due to additional spin precession about that field. If also the structure length L is chosen such that L(s)>L>L(e), it is possible to `wash out' the quantum interference related to the phase coherence of the `orbital part' of the wave function, retaining at the same time that related to the phase coherence of the spin part and, hence, to reveal the corresponding conductance oscillations. It is also shown that strong modulation of the interference pattern could be achieved in this case.

Negative refractive index metamaterials in the visible spectrum based on Mg B 2 ∕ Si C composites Appl. Phys. Lett. 95, 023306 (2009);All of the proposed ever since designs of metamaterials are characterized by ever-increasing sophistication of fabrication methods. Here, a comparatively simple recipe for the fabrication of a metamaterial, which is both gyrotropic and of the simultaneously negative permittivity and permeability, is proposed. The idea is to make a mixture of three ingredients, where one of them would be responsible for the negativity of l, while the other two would be responsible for the negativity of e. The first component of the mixture is the "swarm" of single-domain ferromagnetic nanoparticles, immersed in a mixture of other two, silver and mercury cadmium telluride. By carrying out the computer simulations, the domains of gyromagnetic metamaterial exist, relative to all parameters characterizing the model, that is, the temperature, external magnetic field, parameters of nano-particles, and the fraction of cadmium in Hg 1Àx Cd x Te-compound as well as relative concentrations of the mixture components are established. V C 2014 AIP Publishing LLC.

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