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arXiv · 1104.5138

Anisotropic Dirac fermions in a Bi square net of SrMnBi2

Joonbum Park·G. Lee·F. Wolff-Fabris·Y. Y. Koh·M. J. Eom·Y. K. Kim·M. A. Farhan·Y. J. Jo·C. Kim·J. H. Shim·J. S. Kim
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Abstract

We report the highly anisotropic Dirac fermions in a Bi square net of SrMnBi2, based on a first principle calculation, angle resolved photoemission spectroscopy, and quantum oscillations for high-quality single crystals. We found that the Dirac dispersion is generally induced in the (SrBi)+ layer containing a double-sized Bi square net. In contrast to the commonly observed isotropic Dirac cone, the Dirac cone in SrMnBi2 is highly anisotropic with a large momentum-dependent disparity of Fermi velocities of ~ 8. These findings demonstrate that a Bi square net, a common building block of various layered pnictides, provide a new platform that hosts highly anisotropic Dirac fermions.

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Joonbum Park, G. Lee, F. Wolff-Fabris, Y. Y. Koh, M. J. Eom, Y. K. Kim, M. A. Farhan, Y. J. Jo, C. Kim, J. H. Shim, J. S. Kim. 2011-04-27. Anisotropic Dirac fermions in a Bi square net of SrMnBi2. https://doi.org/10.1103/physrevlett.107.126402

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