2D Weak Localization in ZnO Nanostripes

Abstract

We fabricated oxygen-deficient ZnO thin films onsapphire substrates via pulsed laser deposition and preciselypatterned them into 70 nm wide stripes using photolithographyand focused ion beam nanomachining. This configuration allowedus to perform a detailed quantitative analysis of the weaklocalization (WL) anisotropy effects in a low-dimensional system.By aligning the magnetic field either parallel or perpendicular tothe stripe plane in a maximum Lorentz force configuration, weuncovered a pronounced anisotropic magnetoresistance at lowtemperatures. Angle-dependent magnetoresistance measurementsfurther elucidated this anisotropy, which is well described by thecombination of Altshuler-Aronov’s 2D WL theory and the twobandmodel for positive magnetoresistance.