Chiral Anomaly and Classical Negative Magnetoresistance of Weyl Metals

We consider the classical magnetoresistance of a Weyl metal in which the electron Fermi surface possess nonzero fluxes of the Berry curvature. Such a system may exhibit large negative magnetoresistance with unusual anisotropy as a function of the angle between the electric and magnetic fields. In this case the system can support a new type of plasma waves. These phenomena are consequences of chiral anomaly in electron transport theory.Comment: 4 pages, 2 figure

A Typology for Quantum Hall Liquids

There is a close analogy between the response of a quantum Hall liquid (QHL) to a small change in the electron density and the response of a superconductor to an externally applied magnetic flux - an analogy which is made concrete in the Chern-Simons Landau-Ginzburg (CSLG) formulation of the problem. As the Types of superconductor are distinguished by this response, so too for QHLs: a typology can be introduced which is, however, richer than that in superconductors owing to the lack of any time-reversal symmetry relating positive and negative fluxes. At the boundary between Type I and Type II behavior, the CSLG action has a "Bogomol'nyi point," where the quasi-holes (vortices) are non-interacting - at the microscopic level, this corresponds to the behavior of systems governed by a set of model Hamiltonians which have been constructed to render exact a large class of QHL wavefunctions. All Types of QHLs are capable of giving rise to quantized Hall plateaux.Comment: 4 +epsilon pages, 1 figure; v2 has added references and minor changes, version published in Phys. Rev. B. (Rapid Communications

Dobrostan psychiczny osób starszych: czynniki społeczne

The article discusses the social factors of psychological well-being of elderly people. Psychological well-being is a personal phenomenon. It forms in the process of human activity and in the system of people`s real relationships with surrounding objects. In old age psychological well-being is determined by different factors. The social factor is one of them. It has been found that higher levels of psychological well-being have those elderly people who do not feel themselves lonely, who have enough opportunities to communicate with other people, who take part in a social life, who live with relatives. Specifics of everyday activity in older age are not substantially related to psychological well-being.У статті розглядаються соціальні чинники психологічного самопочуття літніх людей. Психологічне благополуччя - особистісне явище. Вона формується в процесі людської діяльності та в системі реальних стосунків людей з навколишніми об'єктами. У старості психологічне самопочуття визначається різними факторами. Соціальний фактор - один із них. Було встановлено, що більш високий рівень психологічного самопочуття мають ті літні люди, які не відчувають себе самотніми, які мають достатньо можливостей спілкуватися з іншими людьми, які беруть участь у суспільному житті, які живуть із рідними. Специфіка повсякденної діяльності в старшому віці істотно не пов'язана з психологічним самопочуттям.Artykuł omawia społeczne czynniki dobrostanu psychicznego osób starszych. Dobrostan psychiczny jest zjawiskiem osobistym. Kształtuje się w procesie ludzkiej działalności oraz w systemie rzeczywistych relacji ludzi z otaczającymi obiektami. Na starość dobrostan psychiczny zależy od różnych czynników. Czynnik społeczny jest jednym z nich. Stwierdzono, że wyższy poziom dobrostanu psychicznego mają osoby starsze, które nie czują się samotne, które mają wystarczające możliwości komunikowania się z innymi ludźmi, biorącymi udział w życiu społecznym, żyjącymi z krewnymi. Specyfika codziennej aktywności w starszym wieku nie jest zasadniczo związana z samopoczuciem psychicznym

Mesoscopic mechanism of adiabatic charge transport

We consider adiabatic charge transport through mesoscopic metallic samples caused by a periodically changing external potential. We find that both the amplitude and the sign of the charge transferred through a sample per period are random sample specific quantities. The characteristic magnitude of the charge is determined by the quantum interference.Comment: 4 pages, 2 figure

Kaehler submanifolds with parallel pluri-mean curvature

We investigate the local geometry of a class of K\"ahler submanifolds $M \subset \R^n$ which generalize surfaces of constant mean curvature. The role of the mean curvature vector is played by the $(1,1)$-part (i.e. the $dz_id\bar z_j$-components) of the second fundamental form $\alpha$, which we call the pluri-mean curvature. We show that these K\"ahler submanifolds are characterized by the existence of an associated family of isometric submanifolds with rotated second fundamental form. Of particular interest is the isotropic case where this associated family is trivial. We also investigate the properties of the corresponding Gauss map which is pluriharmonic.Comment: Plain TeX, 21 page

Topologies of nodal sets of random band limited functions

It is shown that the topologies and nestings of the zero and nodal sets of random (Gaussian) band limited functions have universal laws of distribution. Qualitative features of the supports of these distributions are determined. In particular the results apply to random monochromatic waves and to random real algebraic hyper-surfaces in projective space.Comment: 62 pages. Major revision following referee repor

Mesoscopic oscillations of the conductance of disordered metallic samples as a function of temperature

We show theoretically and experimentally that the conductance of small disordered samples exhibits random oscillations as a function of temperature. The amplitude of the oscillations decays as a power law of temperature, and their characteristic period is of the order of the temperature itself

Band structures of P-, D-, and G-surfaces

We present a theoretical study on the band structures of the electron constrained to move along triply-periodic minimal surfaces. Three well known surfaces connected via Bonnet transformations, namely P-, D-, and G-surfaces, are considered. The six-dimensional algebra of the Bonnet transformations [C. Oguey and J.-F. Sadoc, J. Phys. I France 3, 839 (1993)] is used to prove that the eigenstates for these surfaces are interrelated at a set of special points in the Brillouin zones. The global connectivity of the band structures is, however, different due to the topological differences of the surfaces. A numerical investigation of the band structures as well as a detailed analysis on their symmetry properties is presented. It is shown that the presence of nodal lines are closely related to the symmetry properties. The present study will provide a basis for understanding further the connection between the topology and the band structures.Comment: 21 pages, 8 figures, 3 tables, submitted to Phys. Rev.