One dimensional electron gas at the LaAlO_3/SrTiO_3 interface and its transport properties

摘要

Quasi-one-dimensional electron gases (q1DEGs) have been obtained by fabricating LaAlO_3 nanowires, using the technique of electrostatic spinning plus post annealing, above TiO_2-terminated SrTiO_3 substrate. The q1DEG exhibits an electronic transport behavior of variable range hopping with the one dimension characteristic. Visible light illumination produces a strong effect on transport process, depressing the resistance of the q1DEG by a factor up to 8. As expected, gating effect is weak at relative high temperatures, ～3.2% at 150 K and 1.5% at 300 K under a back gate of 200 V. Aided by light illumination, however, the gating effect is 35-fold amplified, and the resistance increases under not only negative gates but also positive gates, different from the normal gating effect without illumination. Possible explanations for these phenomena are given.