EAGER: Universal transport and diamagnetic signatures in non-magnetic topological semimetals with linear magnetoresistance

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Non-technical Absttract: The electrical properties of materials are governed by the quantum mechanical motion of electrons in the material. Materials can be insulators, with very low electrical conductivity, or metals, with high electrical conductivity, depending on how the negatively charged electrons move amongst the stationary and positively charged atomic nuclei. Some materials are semimetals where the properties lie between those of metals and insulators. Recently there has been a great deal of interest in topological semimetals where topology plays a major role in determining their properties. This project will investigate the electrical conduction of topological semimetals under high magnetic field to pinpoint their unique characteristics. The results will enable laboratory tests to separate topological semimetals from more conventional counterparts, and to determine the robustness of topological characteristics under conditions that would be encountered in technological applications. These outcomes can be directly employed in developing fabrication techniques and device design strategies to incorporate the novel properties and functionality of topological semimetals in innovative technologies. Technical Abstract: This project aims to identify the magnetotransport and diamagnetic signatures that distinguish topological semimetals from conventional semimetals with large non-saturating magnetoresistance (MR). The outcomes will clarify the universal features of topological semimetal that are unique characteristics of topological electronic structures and the associated Berry phase. A framework will be developed to characterize the disorder leading to the emergence of linear MR in the high field limit, which is expected to render a better understanding of the roles of disorder in linear MR phenomena in general. The prediction for the emergence of linear MR as a consequence of topological nodes and linear dispersion in band structure will be tested for a broader range of semimetal systems and will uncover the common elements of the linear non-saturating MR phenomena. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.