Direct link between disorder, mobility and magnetoresistance in topological semimetals

Abstract

The extent to which disorder influences the properties of topological semimetals remains an open question and is relevant to both the understanding of topological states and the use of topological materials in practical applications. Here, we achieve unmatched and systematic control of point defect concentrations in the prototypical Dirac semimetal Cd${}_3$As${}_2$ to gain important insight into the role of disorder on electron transport behavior. We find that arsenic vacancies introduce localized states near the Fermi level and strongly influence the electron mobility. Reducing arsenic vacancies by changing the As/Cd flux ratio used during deposition results in an increase in the magnetoresistance from 200%-1000% and an increase in mobility from 5000-18,000 cm${}^2$/Vs. However, the degree of linear magnetoresistance, which has previously been linked to disorder, is found here to correlate inversely with measures of disorder, including disorder potential and disorder correlation lengths. This finding yields important new information in the quest to identify the origin of linear magnetoresistance in a wider range of materials.

19 pages, 3 main figures, 4 supplemental figures

References in corpus (7)

• Quantum transport evidence for a three-dimensional Dirac semimetal phase in Cd3As2
• Quasiparticle self-consistent $GW$ method; a basis for the independent-particle approximation
• Linear magnetoresistance caused by mobility fluctuations in the n-doped Cd3As2
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Cited by in corpus (1)

• Doping Topological Dirac Semimetal with magnetic impurities: electronic structure of Mn-doped Cd${}_3$As${}_2$