Abstract
We report resistance-temperature, conductance-voltage, and voltage–magnetic-field measurements in a range of small-area junctions between colossal magnetoresistive materials and the high-temperature superconductor (YBCO). We identify two forms of behavior. In one form the resistance of the junction falls with decreasing temperature and is associated with zero bias conductance peaks. In the other form the resistance rises below some characteristic temperature . In this latter case there is no zero bias conductance peak, but there are small peaks in the voltage–magnetic-field behavior below . We tentatively associate with the pseudogap temperature and argue that the observed effects result from an interaction between the spin-polarized current and the antiferromagnetic spin fluctuations of the pseudogap state.
3 More- Received 22 September 2004
DOI:https://doi.org/10.1103/PhysRevB.71.184517
©2005 American Physical Society