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: $E_{b1}=0.224\pm 0.003$ eV related to conductivity recovery near 70 K and $E_{b2}=0.44\pm 0.015$ eV related to conductivity recovery near 160 K. We discuss possible linkage to structural defects such as dislocations and twin boundaries.