Quantum critical behaviour of the plateau-insulator transition in the quantum Hall regime

High-field magnetotransport experiments provide an excellent tool to investigate the plateau-insulator phase transition in the integral quantum Hall effect. Here we review recent low-temperature high-field magnetotransport studies carried out on several InGaAs/InP heterostructures and an InGaAs/GaAs quantum well. We find that the longitudinal resistivity $\rho_{xx}$ near the critical filling factor $\nu_{c}$ ~ 0.5 follows the universal scaling law $\rho_{xx}(\nu, T) \propto exp[-\Delta \nu/(T/T_{0})^{\kappa}]$, where $\Delta \nu =\nu -\nu_{c}$. The critical exponent $\kappa$ equals $0.56 \pm 0.02$, which indicates that the plateau-insulator transition falls in a non-Fermi liquid universality class.Comment: 8 pages, accepted for publication in Proceedings of the Yamada Conference LX on Research in High Magnetic Fields (August 16-19, 2006, Sendai

Fractional charge in transport through a 1D correlated insulator of finite length

Transport through a one channel wire of length $L$ confined between two leads is examined when the 1D electron system has an energy gap $2M$: $M > T_L \equiv v_c/L$ induced by the interaction in charge mode ($v_c$: charge velocity in the wire). In spinless case the transformation of the leads electrons into the charge density wave solitons of fractional charge $q$ entails a non-trivial low energy crossover from the Fermi liquid behavior below the crossover energy $T_x \propto \sqrt{T_L M} e^{-M /[T_L(1-q^2)]}$ to the insulator one with the fractional charge in current vs. voltage, conductance vs. temperature, and in shot noise. Similar behavior is predicted for the Mott insulator of filling factor $\nu = integer/(2 m')$.Comment: 5 twocolumn pages in RevTex, no figure

Threshold features in transport through a 1D constriction

Suppression of electron current $\Delta I$ through a 1D channel of length $L$ connecting two Fermi liquid reservoirs is studied taking into account the Umklapp electron-electron interaction induced by a periodic potential. This interaction causes Hubbard gaps $E_H$ for $L \to \infty$. In the perturbative regime where $E_H \ll v_c/L$ ($v_c:$ charge velocity), and for small deviations $\delta n$ of the electron density from its commensurate values $- \Delta I/V$ can diverge with some exponent as voltage or temperature $V,T$ decreases above $E_c=max(v_c/L,v_c \delta n)$, while it goes to zero below $E_c$. This results in a nonmonotonous behavior of the conductance.Comment: Final variant published in PRL, 79, 1714; minor correction

Broken symmetry, hyper-fermions, and universal conductance in transport through a fractional quantum Hall edge

We have found solution to a model of tunneling between a multi-channel Fermi liquid reservoir and an edge of the principal fractional quantum Hall liquid (FQHL) in the strong coupling limit. The solution explains how the absence of the time-reversal symmetry at high energies due to chiral edge propagation makes the universal two-terminal conductance of the FQHL fractionally quantized and different from that of a 1D Tomonaga-Luttinger liquid wire, where a similar model but preserving the time-reversal symmetry predicts unsuppressed free-electron conductance.Comment: 5 twocolumn pages in RevTex, no figures, more explanations added, a short version was published in JETP Letters, vol.74, 87 (2001

The moving boundary problem in the presence of a dipole magnetic field

An exact analytic solution is obtained for a uniformly expanding, neutral, infinitely conducting plasma sphere in an external dipole magnetic field. The electrodynamical aspects related to the radiation and transformation of energy were considered as well. The results obtained can be used in analyzing the recent experimental and simulation data.Comment: 17 pages, 1 figure, Submitted to J. Phys. A, Math. and Genera

PHARMACOECONOMICS OF APPLICATION OF HEPATOPROTECTORS IN THERAPY OF DRUG-INDUCED LIVER INJURY AFTER CHEMOTHERAPY

One of the major problems of modern oncology drug is liver damage, requiring additional costs for its treatment. The aim of our work was to study medical and economic efficiency of various schemes of hepatoprotective treatment of toxic liver damage. The paper presents the use of pharmacoeconomic studies in the treatment of hepatic drug-induced hepatitis, which occurs after chemotherapy in patients with Hodgkin's lymphoma. The study was conducted in the two comparison groups on a "cost - effectiveness". This method was chosen because it is in effect depending on the process (method), treatment was varied, as well as costs incurred. The unit of the effect of the number of days required for the relief of hepatic failure has been selected. Economic analysis of the work includes not only toxic hepatitis therapy, and treatment of any disease complications such as hepatic encephalopathy. The study revealed that the effectiveness of therapy increased 1.4 times and the economic costs were 51.8 % reduced with hepatoprotective drug "remaxol"

Is there a renormalization of the 1D conductance in Luttinger Liquid model?

Properties of 1D transport strongly depend on the proper choice of boundary conditions. It has been frequently stated that the Luttinger Liquid (LL) conductance is renormalized by the interaction as $g \frac{e^2} {h}$. To contest this result I develop a model of 1D LL wire with the interaction switching off at the infinities. Its solution shows that there is no renormalization of the universal conductance while the electrons have a free behavior in the source and drain reservoirs.Comment: 5 pages, RevTex 2.0, attempted repair of tex error

Interaction Constants and Dynamic Conductance of a Gated Wire

We show that the interaction constant governing the long-range electron-electron interaction in a quantum wire coupled to two reservoirs and capacitively coupled to a gate can be determined by a low frequency measurement. We present a self-consistent, charge and current conserving theory of the full conductance matrix. The collective excitation spectrum consists of plasma modes with a relaxation rate which increases with the interaction strength and is inversely proportional to the length of the wire. The interaction parameter is determined by the first two coefficients of the out-of-phase component of the dynamic conductance measured at the gate.Comment: 4 pages, LaTeX, 2 figure

EPIZOOTIOLOGICAL-EPIDEMIOLOGICAL SITUATION ON BRUCELLOSIS IN THE RUSSIAN FEDERATION IN 2016 AND PROGNOSIS FOR 2017

The article presents analysis of human and animal incidence of brucellosis in the Russian Federation in 2016. Epidemiological situation on brucellosis is characterized as unstable. Outlined has been the decrease in the number of newly diagnosed brucellosis cases in humans (15.8 %) against the background of the increasing trend for distress and deterioration of the epizootiological situation on brucellosis among the cattle in the regions with well-developed animal husbandry. Cases of group infection among the population in three constituent entities (Stavropol Region, Samara and Leningrad Regions) have been registered, which are of sporadic nature. According to the Federal Service for Veterinary and Phytosanitary Surveillance, mid-term forecast of epizootiological situation on brucellosis in Russia is unfavorable, which under the current trend constitutes a real risk of widespread brucellosis among the livestock in the regions of the Central and Volga Federal Districts. In 2017, we can predict maintaining of the unstable situation on the disease, morbidity rates among the population varying within the range of 340–370 cases

Negative local resistance caused by viscous electron backflow in graphene

Graphene hosts a unique electron system in which electron-phonon scattering is extremely weak but electron-electron collisions are sufficiently frequent to provide local equilibrium above liquid nitrogen temperature. Under these conditions, electrons can behave as a viscous liquid and exhibit hydrodynamic phenomena similar to classical liquids. Here we report strong evidence for this transport regime. We find that doped graphene exhibits an anomalous (negative) voltage drop near current injection contacts, which is attributed to the formation of submicrometer-size whirlpools in the electron flow. The viscosity of graphene's electron liquid is found to be ~0.1 m$^2$ /s, an order of magnitude larger than that of honey, in agreement with many-body theory. Our work shows a possibility to study electron hydrodynamics using high quality graphene