Nearly massless Dirac fermions hosted by Sb square net in BaMnSb2
| Autor: | Leonard Spinu, Alyssa Chuang, Huibo Cao, S. M. A. Radmanesh, Irinel Chiorescu, David Graf, Jinyu Liu, Yanglin Zhu, D. J. Adams, Jin Hu, Zhiqiang Mao |
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| Rok vydání: | 2016 |
| Předmět: |
Free electron model
FOS: Physical sciences 02 engineering and technology Electronic structure 01 natural sciences Article symbols.namesake Effective mass (solid-state physics) 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Antiferromagnetism 010306 general physics Quantum Physics Condensed Matter - Materials Science Multidisciplinary Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Materials Science (cond-mat.mtrl-sci) 021001 nanoscience & nanotechnology 3. Good health Massless particle Dirac fermion Geometric phase symbols Condensed Matter::Strongly Correlated Electrons 0210 nano-technology |
| Zdroj: | Scientific Reports |
| DOI: | 10.48550/arxiv.1605.04613 |
| Popis: | Layered compounds AMnBi2 (A=Ca, Sr, Ba, or rare earth element) have been established as Dirac materials. Dirac electrons generated by the two-dimensional (2D) Bi square net in these materials are normally massive due to the presence of a spin-orbital coupling (SOC) induced gap at Dirac nodes. Here we report that the Sb square net in an isostructural compound BaMnSb2 can host nearly massless Dirac fermions. We observed strong Shubnikov-de Haas (SdH) oscillations in this material. From the analyses of the SdH oscillations, we find key signatures of Dirac fermions, including light effective mass (~0.052m0; m0, mass of free electron), high quantum mobility (1280 cm2V-1S-1) and a Pi Berry phase accumulated along cyclotron orbit. Compared with AMnBi2, BaMnSb2 also exhibits much more significant quasi two-dimensional (2D) electronic structure, with the out-of-plane transport showing nonmetallic conduction below 120K and the ratio of the out-of-plane and in-plane resistivity reaching ~670. Additionally, BaMnSb2 also exhibits an antiferromagnetic order with a weak ferromagnetic component. The combination of nearly massless Dirac fermions on quasi-2D planes with a magnetic order makes BaMnSb2 an intriguing platform for seeking novel exotic phenomena of massless Dirac electrons. Comment: crystal lattice and magnetic structure information addded; final version for publication |
| Databáze: | OpenAIRE |
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