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G Zaránd

Publications and source records attributed to G Zaránd.

10 recordsLinked to original sources

Dynamics of a tunneling magnetic impurity: Kondo effect induced incoherence.

We study how the formation of the Kondo compensation cloud influences the dynamical properties of a magnetic impurity that tunnels between two positions in a metal. The Kondo effect dynamically generates a strong tunneling impurity-conduction electron coupling, changes the temperature dependence of the tunneling rate, and may ultimately result in the destruction of the coherent motion of the particle at zero temperature. We find an interesting two-channel Kondo fixed point as well for a vanishing overlap between the electronic states that screen the magnetic impurity. We propose experiments where the predicted features could be observed.

Journal Article↗

Theory of "ferrisuperconductivity" in U1-xThxBe13.

We construct a two component Ginzburg-Landau theory with coherent pair motion and incoherent quasiparticles for the phase diagram of U1-xThxBe13. The two staggered superconducting states live at the Brillouin zone center and the zone boundary and coexist for temperatures T<or=Tc2 at concentrations xc1 approximately 0. 02<or=x<or=xc2 approximately 0.04. We predict below Tc2 the appearance of a charge density wave (CDW) and Be-sublattice distortion. The distortion explains the muon spin relaxation anomaly; Th-impurity mediated scattering of ultrasound to CDW fluctuations explains the attenuation peak.

Journal Article↗