Remote Mesoscopic Signatures of Induced Magnetic Texture in Graphene

TL;DR

This paper demonstrates how remote magnetic textures in graphene can cause giant conductance fluctuations, breaking the universality of mesoscopic conductance behavior in phase-coherent transport.

Contribution

It reveals the influence of remote magnetic textures on conductance fluctuations in graphene, showing a breakdown of mesoscopic universality due to remote phenomena.

Findings

Giant conductance fluctuations observed far from magnetic textures

Breakdown of universal conductance fluctuation behavior

Remote magnetic textures significantly influence phase-coherent transport

Abstract

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this work, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much larger than $e^2/h$. This violation of one of the fundamental tenets of mesoscopic physics dramatically demonstrates how local considerations can be overwhelmed by remote signatures in phase-coherent conductors