Thermally activated recovery of electrical conductivity in LaAlO3/SrTiO3

Patterned structures of LaAlO3/SrTiO3 that exhibit a decrease in their electrical conductivity below 30 K recover their higher conductivity upon warming in a thermally activated process. Two dominant energy barriers E-b are identified: E-b1 = 0.224 +/- 0.003 eV related to conductivity recovery near 70 K and E-b2 = 0.44 +/- 0.015 eV related to conductivity recovery near 160 K. We discuss possible linkage to structural defects such as dislocations and twin boundaries. DOI: 10.1103/PhysRevB.87.125110