Zero-bias anomalies in low-doped La _1−x Ca _x MnO ₃ manganite single crystals

Abstract

Conductivity of current-biased La0.82 Ca0.18 MnO3 low-doped manganite single crystals has been investigated in wide temperature and magnetic field ranges. Strong zero-bias anomalies in the form of conductance minima and maxima have been observed below the Curie temperature TC. Applied magnetic field and temperature strongly affect the anomaly and cause its transition from the conductance minimum to the conductance maximum. The observed anomalies are ascribed to Anderson localisation and combined Kondo and Fano effects.