Zeeman spin-orbit coupling in antiferromagnetic conductors

This article is a brief review of Zeeman spin-orbit coupling, arising in a low-carrier commensurate N\'eel antiferromagnet subject to magnetic field. The field tends to lift the degeneracy of the electron spectrum. However, a hidden symmetry protects double degeneracy of Bloch eigenstates at special momenta in the Brillouin zone. The effective transverse $g$-factor vanishes at such points, thus acquiring a substantial momentum dependence, which turns a textbook Zeeman term into a spin-orbit coupling. After describing the symmetry underpinnings of the Zeeman spin-orbit coupling, I compare it with its intrinsic counterparts such as Rashba coupling, and then show how Zeeman spin-orbit coupling may survive in the presence of intrinsic spin-orbit coupling. Finally, I outline some of the likely experimental manifestations of Zeeman spin-orbit coupling, and compare it with similar phenomena in other settings such as semiconducting quantum wells.Comment: Review article for the topical issue on Spin-Orbit-Coupled Materials of the Journal of Physics and Chemistry of Solid

Quantum Lifshitz Point

I study a quantum Lifshitz point in a three-dimensional itinerant antiferromagnet, in particular the scaling of the N\'{e}el temperature, the correlation length, the staggered susceptibility, the specific heat coefficient and the resistivity. At low temperatures, the model is shown to have the inverse staggered susceptibility and the resistivity varying as T$^{5/4}$, and the specific heat coefficient varying as T$^{1/4}$

სახელმწიფო საზღვრის გატარების ფიზიკურ-გეოგრაფიული ასპექტები (საქართველოს მაგალითზე) Physical-geographical Aspects Determining the Changes of State Border (On the Example of Georgia)

The work deals with analysis of physical-geographical aspects determining the historical changes of state border on the example of Georgia. Due to the research were identified and classified the geographical factors causing the transformations of the state border, also were determined the sensitivity of each sectors state border of Georgia. So, the uneven territorial distribution of sensitivity along the state border were revealed very sensitive, sensitive, moderately sensitive, stable and very stable sections. Almost 60% of the state border of Georgia is very sensitive. Such types of sectores are represented along the south and east parts of state border of Georgia. Historically the frequent transformations are character here

Gravitational Waves from Mirror World

In this paper we consider the properties of the 10 confirmed by the LIGO Collaboration gravitational wave signals from the black hole mergers. We want to explain non-observation of electromagnetic counterpart and higher then expected merging rates of these events, assuming the existence of their sources in the hidden mirror universe. Mirror matter, which interacts with our world only through gravity, is a candidate of dark matter and its density can exceed ordinary matter density five times. Since mirror world is considered to be colder, star formation there started earlier and mirror black holes had more time to pick up the mass and to create more binary systems within the LIGO reachable zone. In total, we estimate factor of 15 amplification of black holes merging rate in mirror world with respect to our world, which is consistent with the LIGO observations.Comment: "Physics" version. arXiv admin note: substantial text overlap with arXiv:1902.0542