Observation of quantum interference conductance fluctuations in metal rings with strong spin–orbit coupling

Abstract

We investigated the magnetotransport properties of mesoscopic platinum nanostructures (wires and rings) with sub-100 nm lateral dimensions at very low temperatures. Despite the strong spin–orbit interaction in platinum, oscillation of the conductance as a function of the external magnetic field due to quantum interference effects was found to appear. The oscillation was decomposed into Aharonov–Bohm periodic oscillations and aperiodic fluctuations of the conductance due to a magnetic flux piercing the loop of the ring and the metal wires forming the nanostructures, respectively. We also investigated the magnetotransport under different bias currents to explore the interplay between electron phase coherence and spin accumulation effects in strong spin–orbit conductors.

Deciphering quantum fingerprints in electric conductance

“…If the phase is an even multiple of π, constructive interference of the electrons enhances the wave nature and electric conductance. When the phase is an odd multiple of π, on the other hand, destructive interference reduces electric conductance, giving rise to a periodic oscillation of the conductance with respect to the external field, called an Aharonov-Bohm oscillation 3,4,5,6 . In a real nanometal, however, there are many scatterers for the electron waves, such as impurities and nanostructures (Fig.…”