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In this work we examined the possibility of fabricating the metamaterial in a relatively simple way. Our idea was to use the three-component mixture of ingredients, where one of them is responsible for the negative permeability μ(ω) of hypothetical metamaterial, while the other two cause the negative value of effective permittivity ε(ω). In our previous work, we considered Hg1-xCdxTe semiconductor compound as one of the ingredients of mixture. As fabrication of the Hg1-xCdxTe is related to using mercury which is very poisoning, we tried to exclude this material. In the work we proved by numerical simulations the possibility of substituting mercury cadmium telluride by Pb1-xSnxTe. We have shown by computer simulations that by the proper fitting of the parameters, e.g. the radius of nanoparticles, their magnetic moments, the relative concentration of ingredients, etc., it is possible to obtain the metamaterial with negative refraction index in a relatively broad range of temperatures and magnetic fields. The last seems to be very promising in terms of practical applications of metamaterials. [ABSTRACT FROM AUTHOR]

In the paper, a simple theory of quantum inteference in a loop structure caused by spin coherent transport and the Larmor precession of the electron spin is presented. A "spin ballistic" regime is supposed to occur, when the phase relaxation length for the spin part of the wavefunction (Lɸ(s)) is much greater than the phase relaxation length for the "orbital part" (Lɸ(e)). In the presence of an additional magnetic field, the spin part of the electron wavefunction acquires a phase shift due to additional spin precession around that field. If the structure length L is chosen to be Lɸ(s)) > Lɸ(e)) it is possible to "wash out" the quantum interference related to the phase coherence of the "orbital part" of the wavefunction, retaining at the same time that related to the phase coherence of the spin part and, hence, to reveal corresponding conductance oscillations. Different mechanisms of spin relaxation, such as Elliot - Yafet, the scattering by the edges and surface the structure and the precession ones, as well as their influence on the spin coherent transport are considered. The quantum interference in time-dependent magnetic field, quantum beats in mesoscopic loop structure, are also discussed. The similarities between this effect and Josephson, scalar Aharonov - Bohm and Aharonov - Casher effects, as well as their differences are treated and possible application of the effect to the construction of the device, complementary to superconducting quantum interference device is analyzed. [ABSTRACT FROM AUTHOR]

In this work we studied the charge carriers behaviour in quantum structures where the symmetry with respect to space coordinates and time-reversal symmetry are broken simultaneously. As the model of such structures we considered finite semiparabolic quantum well (we considered earlier the case of triangular QW) placed in external magnetic field. We have shown by numerical analysis that the energy spectra of charge carriers in such structures are anisotropic with respect to in-plane (transverse) motion ϵn(+kx) 6= ϵn(-kx). This leads to the anisotropy of charge carriers in-plane momentum transfer which, in its turn leads to the anisotropy of photoconductivity σ(+kx) 6= σ(-kx) and as it follows from our calculations, the effect though not very great, could be measurable for the magnetic field of about few T. [ABSTRACT FROM AUTHOR]