Strong Aharonov-Bohm quantum interference in simply-connected LaAlO${}_3$/SrTiO${}_3$ structures

Abstract

We report Aharonov-Bohm (AB)-type quantum interference in simply-connected devices created at the LaAlO${}_3$/SrTiO${}_3$ interface using conductive-atomic force microscope (c-AFM) lithography. The oscillations are multi-periodic functions of magnetic field strength, and they exhibit a substantial magnetic hysteresis with frequencies that depends on the magnetic sweep direction. The oscillation amplitude for the lowest two frequencies approaches $e^2/h$, consistent with the theoretical maximum for the AB effect, and harmonics up to third order are observable. Broadband quasiperiodic behavior is reported in a fraction of simply-connected electron waveguide devices that exhibit magnetic asymmetries. Curiously, nanoscale ring devices that are multiply-connected lack signatures of AB quantum interference. The interference phenomena are associated with an inhomogeneous magnetic landscape within the LaAlO${}_3$/SrTiO${}_3$ nanostructures.

5 pages, 3 figures, Supplementary materials

References in corpus (3)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Aharonov-Bohm oscillations and magnetic focusing in ballistic graphene rings