arXiv subjects

E. G. Batyev

Publications and source records attributed to E. G. Batyev.

4 recordsLinked to original sources

arXiv2013

Properties of Bose gas in a lattice model (strong interaction)

The doubts concerning validity of gas approximation for strong interaction (for example, hard spheres) are expressed. A contradictory example - a Bose system in a lattice model - is considered. Namely, the X-Y model for spin 1/2 is taken. A state with spins directed downwards is considered to be vacuum with respect to the particles. An inverse spin (+1/2) corresponds to a particle. There is an usual band spectrum (one band) for a single particle. A trial function is written for a multiple particle system. This function was shown to be a good one within a macroscopic limit, when the particle and lattice site numbers tend to infinity (the ratio of energy standard deviation to average energy tends to zero). A result within the gas limit (particle number is small compared with the lattice site number) is compared with that obtained via generally accepted approach.

cond-mat.other↗

arXiv2011

Superconducting Plate in Transverse Magnetic Field: New State

A model to describe Cooper pairs near the transition point (on temperature and magnetic field), when the distance between them is big compared to their sizes, is proposed. A superconducting plate whose thickness is less than the pair size in the transverse magnetic field near the critical value $H_{c2}$ is considered as an application of the model. A new state that is energetically more favourable than that of Abrikosov vortex state within an interval near the transition point was obtained. The system's wave function in this state looks like that of Laughlin's having been used in fractional quantum Hall effect (naturally, in our case - for Cooper pairs as Bose-particles) and it corresponds to homogeneous incompressible liquid. The state energy is proportional to the first power of value $(1 - H/H_{c2})$, unlike the vortex state energy having this value squared. The interval of the new state existence is greater for dirty specimens.

cond-mat.supr-con↗

arXiv2007

Superconducting state of excitonic insulator

A state of an excitonic insulator with the electric current is studied. Initially, in the metallic phase, the electrons and holes are assumed to be moving in the opposite directions, so as the electric current exists. This state is supported by an external condition (the specimen is in an electric circuit with the current). When the temperature decreases, the transition to the ordering state due to formation of the electron--hole pairs is possible (similar to the ordinary state of the excitonic insulator). The properties of the state at zero temperature are investigated. The spectrum of elementary excitations has a gap, and so the conclusion can be made that obtained state is superconducting one. Thus, depending on the external conditions, excitonic insulator behaves itself like the insulator or superconductor. That is correct in the limit of strong overlapping of the electron--hole pairs.

cond-mat.supr-con↗

arXiv2003

Magnetoresistance of a Wigner liquid in a parallel magnetic field

It is assumed that in a two-dimensional electron system with strong correlation (a Wigner liquid), appearance of some relatively slow-moving objects (clusters) composed of small number of electrons is possible. Such clusters may exist in addition to ordinary mobile carriers of the Fermi type. They can pin to inhomogeneities and play the role of additional scatterers. The clusters composed of two and three electrons are discussed (for near order as in triangular lattice). The number of the clusters depends on temperature and a parallel magnetic field (so accordingly for conductivity and magnetization). In the frame of a simple model, a resistivity increasing and a metal-insulator transition with an increasing of a magnetic field are proved. Near this transition, the resistivity changes with temperature according to a linear law. The model gives a nonlinear dependence of magnetization on a magnetic field.

cond-mat.str-el↗