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M. V. Entin

Publications and source records attributed to M. V. Entin.

49 records · Page 3Linked to original sources
arXiv2008

High-frequency blockade in a tight-binding one-dimensional lattice with single vibrating atomic state

One-dimensional tight-binding lattice, single site of which possesses harmonically vibrating level is studied. The states of non-interacting electrons incident with fixed energy from infinity are considered. It is shown that at definite conditions the site reflects electrons {\it absolutely and elastically} (high-frequency blockade states). The problem is treated both numerically and (in the case of narrow band) analytically. The results are compared with the free-electron 1D problem with vibrating $δ$-functional potential. Together with the blockade states the local and reflectionless states are examined. Possible realization of the system as a lattice of quantum dots is discussed.

cond-mat.mes-hall↗
arXiv2007

Photogalvanic current in artificial asymmetric nanostructures

We develop a theoretic description of the photogalvanic current induced by a high frequency radiation in asymmetric nanostructures and show that it describes well the results of numerical simulations. Our studies allow to understand the origin of the electronic ratchet transport in such systems and show that they can be used for creation of new types of detectors operating at room temperature in a terahertz radiation range.

cond-mat.mes-hall↗
arXiv2006

Theory of one-dimensional double-barrier quantum pump in two-frequency signal regime

A one-dimensional system with two $δ$-like barriers or wells bi-chromaticaly oscillating at frequencies $ω$ and $2ω$ is considered. The alternating signal leads to the direct current across the structure (even in a symmetric system). The properties of this quantum pump are studied in a wide range of the system parameters.

cond-mat.mes-hall↗
arXiv2005

Photocurrent in nanostructures with asymmetric antidots

The steady current induced by electromagnetic field in a 2D system with asymmetric scatterers is studied. The scatterers are assumed to be oriented cuts with one diffusive and another specular sides. Besides, the existence of isotropic impurity scatterers is assumed. This simple model simulates the lattice of half-disk which have been studied numerically recently. The model allows the exact solution in the framework of the kinetic equation. The static current response in the second order of electric field is obtained. The photogalvanic tensor contains both responses to linear and circular polarization of electromagnetic field. The model possesses non-analyticity with regards to the rate of impurity scattering.

cond-mat.mes-hall↗
arXiv2005

Properties of 1D two-barrier quantum pump with harmonically oscillating barriers

We study a one-dimensional quantum pump composed of two oscillating delta-functional barriers. The linear and non-linear regimes are considered. The harmonic signal applied to any or both barriers causes the stationary current. The direction and value of the current depend on the frequency, distance between barriers, value of stationary and oscillating parts of barrier potential and the phase shift between alternating voltages.

cond-mat.mes-hall↗
arXiv2004

Suppression of spin-orbit effects in 1D system

We report the absence of spin effects such as spin-galvanic effect, spin polarization and spin current under static electric field and inter-spin-subband absorption in 1D system with spin-orbit interaction of arbitrary form. It was also shown that the accounting for the direct interaction of electron spin with magnetic field violates this statement.

cond-mat.mes-hall↗
arXiv2003

Distribution of equilibrium edge currents

We have studied the distribution of equilibrium edge current density in 2D system in a strong (quantizing) magnetic field. The case of half plane in normal magnetic field has been considered. The transition from classical strong magnetic field to ultraquantum limit has been investigated. We have shown that the edge current density oscillates and decays with distance from the edge. The oscillations have been attributed to the Fermi wavelength of electrons. The additional component of the current smoothly depending on the distance but sensitive to the occupation of Landau levels has been found. The temperature suppression of oscillations has been studied.

cond-mat.mes-hall↗
arXiv1999

Polarizability of 2D monster and light scattering

The electrostatics of 2D system with complicated inner boundary is studied. The object which we call "monster" is built by an iterative process of multiple conformal mapping of the circle exterior. The procedure leads to the figures built from circle with branching curved cuts (i), to the multiple tangential near-round circles (ii) and the Mandelbrot map (iii). The polarizability of a monster in the homogeneous external field is found. The light scattering cross-section was expressed through the polarizability of a monster.

cond-mat.dis-nn↗
arXiv1999

Equilibrial Charge of Grains and Low-temperature Conductivity of Granular Metals

The low-temperature equilibrial state of a system of small metal grains, embedded into insulator, is studied. We find, that the grains may be charged due to the fluctuations of the surface energy of electron gas in grains, rather than quantization of electron states. The higherst-occupied level in a grain fluctuates within the range of order of charging energy below the overall chemical potential. The system, called a gapless Hubbard insulator, has no overall energy gap, while the transfer of an electron on finite distances costs finite energy. The ionization energy is determined mostly by the intragrain Coulomb repulsion, rather than a weak intergrain interaction, responsible for the Coulomb gap. The hopping transport in the system is studied. The hopping energy is determined by the charging energy. At low temperature the transport has gapless character.

cond-mat.dis-nn↗
arXiv1997

Scale Invariance in Percolation Theory and Fractals

The properties of the similarity transformation in percolation theory in the complex plane of the percolation probability are studied. It is shown that the percolation problem on a two-dimensional square lattice reduces to the Mandelbrot transformation, leading to a fractal behavior of the percolation probability in the complex plane. The hierarchical chains of impedances, reducing to a nonlinear mapping of the impedance space onto itself, are studied. An infinite continuation of the procedure leads to a fixed point. It is shown that the number of steps required to reach a neighborhood of this point has a fractal distribution.

cond-mat.dis-nn↗
arXiv1997

Power Tails of Electric Field Distribution Function in 2D Metal-Insulator Composites

The 2D "Swiss-cheese" model of conducting media with round insulator inclusions is studied in the 2nd order of inclusion concentration and near the percolation threshold. The electric field distribution function is found to have power asymptotics for fields much exceeding the average field, independently on the vicinity to the threshold, due to finite probability of arbitrary proximity of inclusions. The strong field in the narrow necks between inclusions results in the induced persistent anisotropy of the system. The critical index for noise density is found, determined by the asymptotics of electric field distribution function.

cond-mat.dis-nn↗
arXiv1997

Enhancement of High-Frequency Field in Near-Ideal Metal Mixture

The a.c. electric field distribution is studied in a composite, containing materials with small local losses. The possibility that 2D two-component system can have effective absorption in the absence of local absorption was evidented. We study the second and higher moments of electric field and show that they diverge with the decrease of local absorption. The 3D system near the percolation threshold is also discussed. The observation of giant field fluctuations in granular films is explained.

cond-mat.dis-nn↗