We study Seebeck effect in liquid electrolytes, starting from its simple neutral analog\char22{}thermodiffusion (so-called Ludwig-Soret or Soret effect). It is observed that when two or more subsystems of mobile particles are subjected to the temperature gradient, various types of them respond to it differently. In the case when these fractions, with different mobility parameters (Soret coefficients), are oppositely charged (a case typical for electrolytes), the nonhomogeneous internal electric field is generated. The latter field prevents these fractions from space separation and determines the intensity of the appearing Seebeck effect.

We consider nonreciprocal supercurrent effects in Josephson junctions based on multiband superconductors with a pairing structure that can break time-reversal symmetry. We demonstrate that a nonreciprocal supercurrent can be generally achieved by the cooperation of interband superconducting phase mismatch and interband scattering as well as by multiband phase frustration. The effect of interband impurity scattering indicates that the amplitude and sign of the nonreciprocal supercurrent are sensitive to the interband phase relation. For the case of a three-band superconductor, due to phase frustration, we show that the profile of the supercurrent rectification is marked by a hexagonal pattern of nodal lines with vanishing amplitude. Remarkably, around the nodal lines, the supercurrent rectification amplitude exhibits threefold structures with an alternating sign. We show that the hexagonal pattern and the threefold structure in the interband phase space turn out to be dependent on the tunneling amplitude of each band. These findings provide hallmarks of the supercurrent rectification which can be potentially employed to unveil the occurrence of spin-singlet multiband superconductivity with time-reversal symmetry breaking.

The measurements of the out-of-plane component of resistivity ${\mathrm{\rho }}_{\mathit{c}}$(T,B) in magnetic field in high-quality epitaxial ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{8+\mathit{x}}$ films are presented. We found that ${\mathrm{\rho }}_{\mathit{c}}$(T,B) exhibits a well-pronounced peak at the edge of the superconducting transition. Magnetic field causes both a sizeable increase of the relative magnitude of the peak and a strong shift of its position to lower temperatures. We demonstrate that zero-field data and data for weak magnetic fields B≤1 T are well described within the fluctuation theory taking into account Gaussian approximation in fluctuation behavior. Quantitative fit of the data in the framework of this theory allowed us to extract the effective anisotropy parameter, the quasiparticle relaxation time and the phase pair-breaking relaxation time. We discuss the reasons of the discrepancy between theory and experiment for stronger magnetic fields. © 1996 The American Physical Society.

The detailed analytical and numerical analysis of the electron spectrum, persistent currents, and their densities for an annulus placed in a constant magnetic field (Corbino disk geometry) is presented. We calculate the current density profiles and study their dependence on the inner and outer radii of the annular. We study the evolution of the persistent currents and track their emergence and decay for different limiting cases of such a geometry, starting from a nanodot and ending by a macroscopic circle. Our analytical results for the currents are confirmed by the agreement between the integration of the corresponding current densities and the application of the Byers-Yang formula, when it is applicable. Among other results, we find the general expression for the persistent current in a narrow annulus, which in the one channel approximation reproduces the well-known result for quasi-one-dimensional mesoscopic metallic ring. Moreover, it allows to analyze the multichannel case of a relatively wide annulus. Our study can be used for more accurate treatment and interpretation of the experimental data with measurements of the persistent currents in different doubly connected systems.

In this short review we pass through the milestones in the studies of the electronic topological transitions (ETT) and focus on some recent applications of the ideas worked out in their classical theory. These are: two-dimensional electron systems, de Haas-van Alphen effect, classification of ETT in multidimensional systems, superconductivity in systems close to ETT, and thermoelectricity in heavy-fermion systems where the cascades of topological changes of Fermi surface (FS) are generated by magnetic field. The history of studies of ETT is inextricably linked with Kharkov school of condensed matter physics, with such names as I. M. Lifshitz, V. G. Bar’yakhtar, and many other. Among them is Moisey Isaakovich Kaganov, who contributed much in the studies of the role of geometry and topology of FS in physical properties of the metals. Two of the authors (A.V. and Y.G.) had the honor and pleasure to work with M. I. Kaganov — Y. M. Blanter, M. I. Kaganov, A. V. Pantsulaya, and A. A. Varlamov, Phys. Rep. 245, 159 (1994);¹ all of us have been learning the niceties of science from his books. “The Fermi surface is the stage on which the drama of the life of the electron is played out” wrote Kaganov and Lifshitz. We devote this work to their memory.