Absence of Andreev reflections and Andreev bound states above the critical temperature

作者：Dagan Y^*; Kohen A; Deutscher G; Revcolevschi A

来源：Physical Review B, 2000, 61(10): 7012-7016.

DOI：10.1103/PhysRevB.61.7012

We present measurements of the temperature dependence of the differential conductance of normal-metal/underdoped high-T-c superconductors contacts. Both Y1Ba2Cu3O7-x thin films and La2-xSrxCuO4 single crystals were studied. The effect of direct Andreev reflections, or of Andreev bound states, do not persist above the critical temperature. Our results are consistent with an Andreev energy scale that does not follow the doping dependence of the pseudogap, but rather that of the critical temperature.

• 出版日期2000-3-1