Confined bulk states as a long-range sensor for impurities and a transfer channel for quantum information

We show that confinement of bulk electrons can be observed at low-dimensional surface structures and can serve as a long-range sensor for the magnetism and electronic properties of single impurities or as a quantum information transfer channel with large coherence lengths. Our ab initio calculations reveal oscillations of electron density in magnetic chains on metallic surfaces and help to unambiguously identify the electrons involved as bulk electrons. We furthermore discuss the possibility of utilizing bulk state confinement to transfer quantum information, encoded in an atom's species or spin, across distances of several nanometers with high efficiency.Comment: 5 pages, 2 figure

Beyond the random phase approximation: Stimulated Brillouin backscatter for finite laser coherence times

We develop a statistical theory of stimulated Brillouin backscatter (BSBS) of a spatially and temporally partially incoherent laser beam for laser fusion relevant plasma. We find a new collective regime of BSBS (CBSBS) with intensity threshold controlled by diffraction, an insensitive function of the laser coherence time, $T_c$, once light travel time during $T_c$ exceeds a laser speckle length. The BSBS spatial gain rate is approximately the sum of that due to CBSBS, and a part which is independent of diffraction and varies linearly with $T_c$. We find that the bandwidth of KrF-laser-based fusion systems would be large enough to allow additional suppression of BSBS.Comment: 8 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1105.209

Transient electrophoretic current in a nonpolar solvent

The transient electric current of surfactants dissolved in a nonpolar solvent is investigated both experimentally and theoretically in the parallel-plate geometry. Due to a low concentration of free charges the cell can be completely polarized by an external voltage of several volts. In this state, all the charged micelles are compacted against the electrodes. After the voltage is set to zero the reverse current features a sharp discharge spike and a broad peak. This shape and its variation with the compacting voltage are reproduced in a one-dimensional drift-diffusion model. The model reveals the broad peak is formed by a competition between an increasing number of charges drifting back to the middle of the cell and a decreasing electric field that drives the motion. After complete polarization is achieved, the shape of the peak stops evolving with further increase of the compacting voltage. The spike-peak separation time grows logarithmically with the charge content in the bulk. The time peak is a useful measure of the micelle mobility. Time integration of the peak yields the total charge in the system. By measuring its variation with temperature, the activation energy of bulk charge generation has been found to be 0.126 eV.Comment: 7 pages, 5 figure

On the convergence of the gradient expansion in hydrodynamics

Hydrodynamic excitations corresponding to sound and shear modes in fluids are characterised by gapless dispersion relations. In the hydrodynamic gradient expansion, their frequencies are represented by power series in spatial momenta. We investigate the analytic structure and convergence properties of the hydrodynamic series by studying the associated spectral curve in the space of complexified frequency and complexified spatial momentum. For the strongly coupled ${\cal N}=4$ supersymmetric Yang-Mills plasma, we use the holographic duality methods to demonstrate that the derivative expansions have finite non-zero radii of convergence. Obstruction to the convergence of hydrodynamic series arises from level-crossings in the quasinormal spectrum at complex momenta.Comment: V3: 5 pages, 2 figures. Final version. Published in Physical Review Letters with the title "Convergence of the Gradient Expansion in Hydrodynamics

The complex life of hydrodynamic modes

We study analytic properties of the dispersion relations in classical hydrodynamics by treating them as Puiseux series in complex momentum. The radii of convergence of the series are determined by the critical points of the associated complex spectral curves. For theories that admit a dual gravitational description through holography, the critical points correspond to level-crossings in the quasinormal spectrum of the dual black hole. We illustrate these methods in ${\cal N}=4$ supersymmetric Yang-Mills theory in 3+1 dimensions, in a holographic model with broken translation symmetry in 2+1 dimensions, and in conformal field theory in 1+1 dimensions. We comment on the pole-skipping phenomenon in thermal correlation functions, and show that it is not specific to energy density correlations.Comment: V3: 54 pages, 18 figures. Appendix added. Version to appear in JHE

Types of Angiopathy in Experimental Autoimmune Disease in Rats

The purpose and objectives of this work were to study the nature of the heart, lungs and kidneys angiopathy in rats with a model of systemic autoimmune disease, carrying out comparisons of the results with extravasal morphological manifestations of the pathological process, the state of vascular endothelial function and activity of pro-inflammatory cytokines in the blood. The experiment was conducted on 40 non-linear rats. To simulate the disease animals were injected by complete Freund's adjuvant, a solution of splenic deoxyribonucleic acid cattle, mercaptopurine, methyluracilum and with food rats constantly received sulfate cadmium, lithium hydroxybutyrate and ammonium molybdate. Within two months from the start of the study animals were taken out of the experiment on the background of intraperitoneal nembutal anesthesia. Histological sections of the heart, lung and kidney tissue were stained with hematoxylin -eosin, alcian blue and by van-Gieson, becoming the PAS-reaction. In the animals with the proposed experimental model of systemic autoimmune disease observed morphological characteristics of lesions of the heart blood vessels, lungs and kidneys, the nature of the manifestations of which were interconnected with each other, which confirms the common pathogenetic angiopathy constructions at various diseases in clinical practice. In the genesis of cardiac, pulmonary and renal vessels lesions act the activation of pro-inflammatory cytokines and violation of vascular endothelial function, which has a certain practical significance. In clinical practice, not only purely systemic vasculitis, and other autoimmune diseases should be treated as angiopathy

Implementation of Innovative Technology for Evaluating High-speed Rail Passenger Transportation

The size and content of consumer value (CV) of the service for the transportation of passengers by the railways ofUkrainein long-distance communication by nighttime and daytime trains is determined. A comparison is made of the results of two approaches to researching the attitude of customers to the service – traditional (point-based) and new, taking into account the specific requirements of the total management of the customer value of the service. The directions of the managerial impact of CV on the passenger transportation in long-distance communication by the railways ofUkrainebased on the attitude of customers to the disadvantages and advantages of this service are determined.In three focus groups, discussions were held about travel by Ukrainian railways by daytime and nighttime trains. Based on the results, a list of the disadvantages and advantages that form the consumer value of such a transport service is formed. The list of 19 positive and negative statements reflected all stages of the trip by rail. Behind it, the Likert scale and the corresponding form for conducting an interview were developed. The number of respondents is 823. The sample is random.The results of the polls confidently prove that the prejudiced attitude of passengers towards daytime transportation has been overcome. The ratio of passengers of the railways ofUkrainein daytime transportation in long-distance traffic is better than in nighttime.Only one fifth of those traveling daytime and nighttime are fully satisfied with the level of advantages and disadvantages, which is not enough for most customers to make repeat purchases. However, such a hypothesis needs to be verified in future studies.The feeling of satisfaction among passengers of daytime trains with a positive value of consumer value does not arise in 29 %, which is a threat to the railway operator company. Women are generally worse off on transportation services than men.Personal experience using the train in general does not affect the attitude. However, the experience of using a nighttime train significantly reduces the consumer value of the transport service.The main conclusion is that when several customer segments are served simultaneously in a common space, the total management of the customer value of the service and the corresponding research methods are productive