Direct link between disorder and magnetoresistance in topological semimetals
Jocienne N. Nelson, Ian A. Leahy, Anthony D. Rice, Chase Brooks, Glenn Teeter, Mark van Schilfgaarde, Stephan Lany, B. Fluegel, Minhyea Lee, Kirstin Alberi
Abstract
The extent to which disorder influences the properties of topological semimetals is relevant to the understanding of topological states and their use in practical applications. Using molecular beam epitaxy, we achieve systematic control of point defect concentrations in the prototypical Dirac semimetal ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ to gain insight into the role of disorder on electron transport behavior. Using the guiding center diffusion model for linear magnetoresistance, we extract point defect densities as a function of deposition conditions. We find that reducing cadmium defect concentrations by an order of magnitude results in an $2\ifmmode\times\else\texttimes\fi{}$ increase in the magnetoresistance from 450% to 900%. This finding yields important information in the quest to identify the origin of linear magnetoresistance in a wider range of materials.