Electron tunneling measurement of the energy gap in a LaSrCuO superconductor

Abstract We have used the break junction technique to determine the energy gap of lanthanum—strontium—copper—oxide, one of the new high critical temperature superconductors. The current—voltage characteristics demonstrated a variety of tunneling behaviours. The best characteristic indicating quasiparticle tunneling between superconducting electrodes implied an energy gap of 7.0 ± 0.1 meV. Derivatives of other characteristics showed weak structure indicating possible energy gaps up to 9 meV.