I-V characteristics of atomically thin superconducting $La_{2-x}Sr_xCuO_4$ films

ORAL

Abstract

I-V characteristics of $La_{2-x}Sr_xCuO_4$ thin films grown by Molecular Beam Epitaxy are studied in a wide range of temperatures in zero magnetic field. Strongly nonlinear response to applied electric current was observed near the superconducting state. At temperatures $T>T_{BKT}$ the observed characteristics have three distinct features: (1) at small currents voltage $V$ is proportional to the current $I$; (2) at higher currents a cubic dependence ($I \sim I^3$) is observed; (3) and even higher currents $V \sim I^\alpha$ with coefficient $\alpha(T)<$ 3, which decreases with the temperature increase. At $T=T_{BKT}$ the coefficient $\alpha=3$. Observed nonlinear response is in-line with Berezinsky--Kosterlitz--Thouless (BKT) theory.

*Work was supported by National Science Foundation (ECCS-1128459).

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Authors

  • Scott Dietrich

    • The Graduate Center, City University of New York, New York 10016, USA
    • Physics Department, City College of the City University of New York, New York 10031, USA

  • William Mayer

    • The Graduate Center, City University of New York, New York 10016, USA

  • Sergey Vitkalov

    • Physics Department, City College of the City University of New York, New York 10031, USA

  • Andrey Sergeev

    • SUNY Research Foundation, SUNY at Buffalo, Buffalo, NY14226, USA