Planar configuration of extraordinary magnetoresistance for 2D-material-based magnetic field sensors

Abstract

Nanoscale-resolution magnetic field sensing plays a significant role in fundamental research in a wide range of fields, from material science to biology. Magnetoresistors in particular offer simplicity of construction and easy adaptation for fabrication based on two-dimensional materials, together with the ability to detect small and medium magnetic fields. Among the wide range of magnetoresistance effects, extraordinary magnetoresistance is unique because it does not require a magnetic material as part of its structure, which may be advantageous in certain applications. In this paper we demonstrate that a recently proposed planar configuration of extraordinary magnetoresistance is naturally suited to the fabrication of devices based on two-dimensional materials. Several operating magnetoresistors have been made for this purpose, using epitaxial mono- and bilayer graphene as well as Bi2Se3 microflakes. Besides the implementation of the extraordinary magnetoresistance in a planar configuration, we demonstrate experimentally the consequences of geometry optimization for future applications. Using the finite element method to simulate the extraordinary magnetoresistance effect in a specific hybrid structure containing a 2D sheet, our research goes beyond the experimental framework, and the efficiency of the applied optimization method can be compared to the best results achieved so far in the field.