Onsager-Casimir frustration from resistance anisotropy in graphene quantum Hall devices
Journal
Physical Review B
Journal Volume
104
Journal Issue
8
Date Issued
2021
Author(s)
Hu I.-F
Panna A.R
Rigosi A.F
Kruskopf M
Patel D.K
Liu C.-I
Saha D
Payagala S.U
Newell D.B
Jarrett D.G
Elmquist R.E.
Abstract
We report on nonreciprocity observations in several configurations of graphene-based quantum Hall devices. Two distinct measurement configurations were adopted to verify the universality of the observations (i.e., two-terminal arrays and four-terminal devices). Our findings determine the extent to which epitaxial graphene anisotropies contribute to the observed asymmetric Hall responses. The presence of backscattering induces a device-dependent asymmetry rendering the Onsager-Casimir relations limited in their capacity to describe the behavior of such devices, except in the low-field classical regime and the fully quantized Hall state. The improved understanding of this quantum electrical process broadly limits the applicability of the reciprocity principle in the presence of quantum phase transitions and for anisotropic two-dimensional materials. ? 2021 authors. Published by the American Physical Society.
Subjects
Anisotropy; Graphene; Graphene devices; Phase transitions; Quantum theory; Electrical process; Epitaxial graphene; Measurement configuration; Quantum Hall devices; Quantum phase transitions; Reciprocity principle; Resistance anisotropy; Two-dimensional materials; Hall effect devices
Type
journal article