Detection of magnetic field by extraordinary magnetoresistance sensor
Postdoc Bowen Zhou
Overview
Detection of weak magnetic field in a cheaper and convenient way is one hard task nowadays. Superconducting quantum interference device (SQUID) performs at cryogenic temperature so it is expensive to use. Hall sensor can perform at room temperature but can not compete with SQUID. Extraordinary magnetoresistance (EMR) sensor at room temperature with optimization may outperform Hall sensor and even compete with SQUID.
Background
Extraordinary magnetoresistance effect: At zero B-field, the metal shunt short-circuits current through the middle low-resistivity region of the device. In a perpendicular B-field, the charge carriers are deflected around the shunt as the current density J becomes orthogonal to the interfacial electric field E at the interface of the shunt and the semiconductor. Charge carriers are forced to travel through the longer high-resistivity material around the shunt, leading to a magnetoresistance enhanced over the zero-field value by up to several orders of magnitude.
Objective
We are trying to optimize EMR sensor by shape optimization, parameter optimization, etc. with different materials compositions to enhance its MR, sensitivity, signal-to-noise ratio, and reduce noise-equivalent field.
Contents
(1) Mechanical exfoliation of materials such as graphite, boron nitride, transition metal dichalcogenides for EMR sensor fabrication.
(2) COMSOL simulation on shape optimization and parameter optimization.
(3) Pattern design in software Clewin, etc. for fabrication such as electron beam lithography.
(4) Deep learning for shape and parameter optimization?
(5) Participate in material and sensor characterizations.
(6) Other methods...
Welcome to read my poster outside office 245 in Building 309 for more details.
Interested?
Contact: bowez@dtu.dk
Reference
1. S. A. Solin, T. Thio, D. R. Hines, and J. J. Heremans, “Enhanced roomtemperature geometric magnetoresistance in inhomogeneous narrow-gap semiconductors,” Science 289, 1530–1532 (2000).
2. B. Zhou, K. Watanabe, T. Taniguchi, and E. A. Henriksen, Extraordinary magnetoresistance in encapsulated
monolayer graphene devices, Appl. Phys. Lett. 116, 053102
(2020).