arXiv subjects

Yu. A. Kolesnichenko

Publications and source records attributed to Yu. A. Kolesnichenko.

41 records · Page 3Linked to original sources

arXiv2002

Josephson effect in point contacts between ''f-wave'' superconductors

A stationary Josephson effect in point contacts between triplet superconductors is analyzed theoretically for most probable models of the order parameter in UPt_{3} and Sr_{2}RuO_{4}. The consequence of misorientation of crystals in superconducting banks on this effect is considered. We show that different models for the order parameter lead to quite different current-phase dependences. For certain angles of misorientation a boundary between superconductors can generate the parallel to surface spontaneous current. In a number of cases the state with a zero Josephson current and minimum of the free energy corresponds to a spontaneous phase difference. This phase difference depends on the misorientation angle and may possess any value. We conclude that experimental investigations of the current-phase dependences of small junctions can be used for determination of the order parameter symmetry in the mentioned above superconductors.

cond-mat.supr-con↗

arXiv2000

The influence of single magnetic impurities on the conductance of quantum microconstrictions

The nonlinear ballistic conductance of three-dimensional quantum microconstrictions, which contain magnetic impurities, is investigated. The nonlinear part of the conductance, which is due to the interaction of electrons with magnetic impurities is obtained. The analytical results have been analyzed numerically. It is shown that intensity of the Kondo anomaly in the conductance as the function of the applied voltage depends on the diameter of the constriction and the positions of impurities.

cond-mat.mes-hall↗

arXiv2000

The quantum conductance of ballistic microconstrictions in metals with an open Fermi surface

It is shown that the conductance $G$ of the quantum microconstriction in the metal with an opened Fermi surface as a function of the contact diameter undergoes the jumps $e^{2}/h$ of the opposite sign. The negative jumps is the result of the limitation of the energy of the electron motion along the direction, in which the Fermi surface is opened. The point contact spectrum $dG/dV$ of such constriction has additional peaks at the bias $eV$ when the maximal energy $ε_{\max}$ of the quantum subband is equal to the energies $ε_{F}\pm \frac{eV}{2}$ ($ε_{F}$ is the Fermi energy).

cond-mat.mes-hall↗

arXiv2000

Effect of quantum interference in the nonlinear conductance of microconstrictions

The influence of the interference of electron waves, which were scattered by single impurities, on nonlinear quantum conductance of metallic microconstrictions (as was recently investigated experimentally) is studied theoretically. The dependence of the interference pattern in the conductance $G(V)$ on the contact diameter and the spatial distribution of impurities is analyzed. It is shown that the amplitude of conductance oscillation is strongly depended on the position of impurities inside the constriction.

cond-mat.mes-hall↗

arXiv1999

On the Selfconsistent Theory of Josephson Effect in Ballistic Superconducting Microconstrictions

The microscopic theory of current carrying states in the ballistic superconducting microchannel is presented. The effects of the contact length L on the Josephson current are investigated. For the temperatures T close to the critical temperature T_c the problem is treated selfconsistently, with taking into account the distribution of the order parameter $Δ(r)$ inside the contact. The closed integral equation for $Δ$ in strongly inhomogeneous microcontact geometry ($L\lesssim ξ_{0}, ξ_{0}$ is the coherence length at T=0) replaces the differential Ginzburg-Landau equation. The critical current $I_{c}(L)$ is expressed in terms of solution of this integral equation. The limiting cases of $L\ll ξ_{0}$ and $L\gg ξ_{0}$ are considered. With increasing length L the critical current decreases, although the ballistic Sharvin resistance of the contact remains the same as at L=0. For ultra short channels with $L\lesssim a_{D}$ ($a_{D}\sim v_{F}/ω_{D}, ω_{D}$ is the Debye frequency) the corrections to the value of critical current I_c(L=0) are sensitive to the strong coupling effects.

cond-mat.supr-con↗