Zero-bias anomaly in CrO₂ junctions

Authors

Andrei Sokolov, University of Nebraska-LincolnFollow
C.-S. Yang, University of Nebraska-Lincoln
Lu Yuan, University of Nebraska-LincolnFollow
Sy_Hwang Liou, University of Nebraska-LincolnFollow
Ruihua Cheng, University of Nebraska-Lincoln
H.-K. Jeong, University of Nebraska-LincolnFollow
T. Komesu, University of Nebraska-LincolnFollow
B. Xu, University of Nebraska-Lincoln
C.N. Borca, University of Nebraska-Lincoln
Peter A. Dowben, University of Nebraska-LincolnFollow
Bernard Doudin, University of Nebraska-LincolnFollow

Date of this Version

5-1-2002

Comments

Published by EDP Sciences; Europhys. Letters 58 (2002) 448-454. Copyright 2002. Permission to use.

Abstract

CrO₂thin films, with crystallites of several microns size, provide the opportunity for the investigation of the intergrain tunneling between a few crystals separated by a 1-2 ^nm thick Cr₂O₃ film. A pronounced zero-bias anomaly of the conductance is found at low temperatures. Combined photoemission and inverse photoemission temperature-dependent studies confirm the occurrence of Coulomb blockade. For the strong-tunneling case (^R2), the magnetoresistance decreases strongly with bias. For the weak-tunneling case (^R>>R_Q), the magnetoresistance decreases by a factor two with increasing bias, as predicted by a co-tunneling model.