The Stiffnessometer a magnetic field free superconducting stiffness meter and the nature of the phase transition in cuprates

by Amit Keren

at Condensed Matter Seminar

Mon, 25 Feb 2019, 11:30
Physics building (#54) room 207

Abstract

A new method to measure the superconducting stiffness tensor bar rho s without subjecting the sample to magnetic field is presented and applied to La 1 875 Sr 0 125 CuO 4 LSCO The method is based on the London equation J bar rho sA where J is the current density and A is the vector potential Using rotor free A and measuring J via the magnetic moment of superconducting rings we extract bar rho s The technique named Stiffnessometer is sensitive to very small stiffness which translates to penetration depth on the order of a few millimeters We apply this method to two different LSCO rings: one with the current running only in the CuO2 planes and another where the current must cross planes We find different transition temperatures for the two rings namely there is a temperature range with two dimensional stiffness The Stiffnessometer results are accompanied by Low Energy mSR measurements on the same sample to determine the stiffness anisotropy at favorable temperatures

Created on 22-02-2019 by Bar Lev, Yevgeny (ybarlev)
Updaded on 22-02-2019 by Bar Lev, Yevgeny (ybarlev)