Electronic structure of the candidate 2D Dirac semimetal SrMnSb2: a combined experimental and theoretical study

DOI: 10.21468/SciPostPhys.4.2.010

Authors: Shyama V. Ramankutty (Van der Waals Zeeman Institute, University of Amsterdam) , Jans Henke (Van der Waals Zeeman Institute, Institute for Theoretical Physics, University of Amsterdam) , Adriaan Schiphorst (Van der Waals Zeeman Institute, University of Amsterdam) , Rajah Nutakki (Van der Waals Zeeman Institute, University of Amsterdam) , Stephan Bron (Van der Waals Zeeman Institute, University of Amsterdam) , Georgios Araizi-Kanoutas (Van der Waals Zeeman Institute, University of Amsterdam) , Shrawan K. Mishra (Indian Institute of Technology (BHU)) , Lei Li (Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences) , Yingkai Huang (Van der Waals Zeeman Institute, University of Amsterdam) , Timur Kim (Diamond Light Source) , Moritz Hoesch (Diamond Light Source) , Christoph Schlueter (Diamond Light Source) , Tien-Lin Lee (Diamond Light Source) , Anne De Visser (Van der Waals Zeeman Institute, University of Amsterdam) , Zhicheng Zhong (Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences) , Jasper Van Wezel (Institute for Theoretical Physics, University of Amsterdam) , Erik Van Heumen (Institute for Theoretical Physics, IoP, University of Amsterdam) , Mark Golden (Institute for Theoretical Physics, IoP, University of Amsterdam)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scipost Physics , VOL 4

State: Published (Approved)
Published: February 2018
Diamond Proposal Number(s): 15189 , 16433 , 18410

Abstract: SrMnSb2 is suggested to be a magnetic topological semimetal. It contains square, 2D Sb planes with non-symmorphic crystal symmetries that could protect band crossings, offering the possibility of a quasi-2D, robust Dirac semi-metal in the form of a stable, bulk (3D) crystal. Here, we report a combined and comprehensive experimental and theoretical investigation of the electronic structure of SrMnSb2, including the first ARPES data on this compound. SrMnSb2 possesses a small Fermi surface originating from highly 2D, sharp and linearly dispersing bands (the Y-states) around the (0,π/a)-point in k-space. The ARPES Fermi surface agrees perfectly with that from bulk-sensitive Shubnikov de Haas data from the same crystals, proving the Y−states to be responsible for electrical conductivity in SrMnSb2. DFT and tight binding (TB) methods are used to model the electronic states, and both show good agreement with the ARPES data. Despite the great promise of the latter, both theory approaches show the Y-states to be gapped above EF, suggesting trivial topology. Subsequent analysis within both theory approaches shows the Berry phase to be zero, indicating the non-topological character of the transport in SrMnSb2, a conclusion backed up by the analysis of the quantum oscillation data from our crystals.

Subject Areas: Materials, Physics


Instruments: I05-ARPES , I09-Surface and Interface Structural Analysis

Other Facilities: BESSY-II

Added On: 19/03/2018 10:45

Documents:
SciPostPhys_4_2_010.pdf

Discipline Tags:

Surfaces Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)