Excess current in point contacts on two-band superconductor MgB$_2$ in magnetic field

Yu. G. Naidyuk; O. E. Kvitnitskaya; I. K. Yanson; S. Lee; S. Tajima

doi:10.1016/j.ssc.2004.11.037

paper

Excess current in point contacts on two-band superconductor MgB $_{2}$ in magnetic field

arXiv:cond-mat/0403324 · doi:10.1016/j.ssc.2004.11.037

Abstract

Series of $I (V)$ characteristic and bias-dependent differential resistance $d V / d I (V)$ for point-contacts on the single crystals of two-band superconductor MgB $_{2}$ were measured in magnetic field up to 9 T. We have obtained magnetic field dependences of the excess current on the $I (V)$ curves and analyzed them using Koshelev and Golubov (Phys. Rev. Lett. {\bf 90}, 177002 (2003)) theoretical results for the mixed state of a dirty two-band superconductor. Introducing a simple model for the excess current in the point contact in the mixed state our data can be qualitatively described utilizing theoretical magnetic filed behavior of the $σ$ and $π$ -band superconducting order parameters and the corresponding averaged electronic density of states in MgB $_{2}$ .

4 pages, 3 figs, RevTex4; V2: plain text improved, BTK fit is added to insets of Fig.3

Excess current in point contacts on two-band superconductor MgB2​ in magnetic field

Abstract

Excess current in point contacts on two-band superconductor MgB $_{2}$ in magnetic field