arXiv subjects

S. N. Artemenko

Publications and source records attributed to S. N. Artemenko.

24 records · Page 2Linked to original sources

arXiv1999

On Dissipation Mechanism in the Intrinsic Josephson Effect in Layered Superconductors with d-wave Pairing

Conductivity mechanism in the regime of the intrinsic Josephson effect in layered superconductors with singlet d-wave pairing is studied theoretically. The cases of coherent and incoherent interlayer tunneling of electrons are considered. The theory with coherent tunneling describes main qualitative features of the effect observed in highly anisotropic high-T$_c$ superconductors at voltages smaller than the amplitude of the superconducting gap, mechanism of the resistivity being related to excitations of the quasiparticles via the d-wave gap. At voltages of the order of the gap amplitude and larger, the I-V curves are better described by the incoherent tunneling. Interaction of the Josephson junctions formed by the superconducting layers due to charging effects is shown to be small.

cond-mat.supr-con↗

arXiv1998

Excitation of plasma oscillations by moving Josephson vortices in layered superconductors

In the frame of an exactly solvable model we calculate electric and magnetic fields created by uniformly moving lattice of Josephson vortices driven by the transport current in the magnetic field parallel to conducting layers. The distribution of fields and currents is strongly modified at large velocities of the vortex lattice, plasma oscillations of superconducting electrons being excited by flux flow at low temperatures. This modifies the flux flow resistivity and results in interference features in I-V curves, thus regions of negative differential conductivity appear in which the uniform motion of the vortex lattice is not stable. The spectrum of electromagnetic radiation by moving vortices contains large peaks related to the excitation of plasma oscillations and to the Cherenkov radiation.

cond-mat.supr-con↗

arXiv1997

Collective oscillations in superconductors revisited

In the recent paper Ohashi and Takada (OT) made statements that in the clean limit considered by us (AV) in 1975, weakly damped collective oscillations in superconductors do not exist due to the Landau damping and their spectrum differs from that obtained in AV. In this Comment we would like to note that these statements arise as a result of a misunderstanding of the term "clean" case. OT considered the limit of frequencies larger, than elastic scattering rate, meanwhile AV obtained weakly damped mode in the case when temperature is larger than scattering rate, the frequencies being smaller (!) than elastic scattering rate. All these problems were discussed in our review article in 1979 which was, presumably, unknown to OT.

cond-mat.supr-con↗

arXiv1997

Character of electron reflection at a normal metal-Peierls semiconductor boundary

The reflection of electrons incident from a normal metal on the boundary of the metal with a quasi-one-dimensional conductor containing a charge-density wave (CDW) is investigated theoretically. It is shown that the reflection is not of an Andreev character, as it was suggested earlier, but rather of a Bragg character. This is due to the fact that the CDW is actually an electronic crystal, and its wave vector is a reciprocal lattice vector of the electronic crystal. The ratio of the intensities of the standard and Bragg reflection depends on the phase of the CDW.

cond-mat↗

arXiv1997

Intrinsic Josephson Effect and Violation of the Josephson Relation in Layered Superconductors

Equations describing the resistive state of a layered superconductor with anisotropic pairing are derived. The similarity with a stack of Josephson junctions is found at small voltages only, when current density in the direction perpendicular to the layers can be interpreted as a sum of the Josephson superconducting, the Ohmic dissipative and the interference currents. In the spatially uniform state differential conductivity at higher voltages becomes negative. Nonuniformity of the current distribution generates the branch imbalance and violates the Josephson relation between frequency and voltage.

cond-mat.supr-con↗

arXiv1997

Linear response and collective oscillations in superconductors with d-wave pairing

Simple and physically transparent equations for the linear response of layered superconductors with d-wave symmetry of the order parameter are derived by means of the quasiclassic kinetic theory of superconductivity. Responses to solenoidal and potential electric fields have different frequency dependencies. The conductivity describing the response to the solenoidal field is limited by the momentum relaxation, like in a normal metal. The response to the potential electric field depends, in addition, on the branch imbalance relaxation rate. The damping of plasma oscillations of superconducting electrons is determined by dielectric relaxation and is small. Relaxation of branch imbalance determined by elastic scattering is large enough to make the Carlson-Goldman mode in d-wave superconductors overdamped.

cond-mat.supr-con↗