Scanning Tunneling Microscopy Studies of the Topological Insulator Candidate YbB$_6$

ORAL

Abstract

We report scanning tunneling microscopy studies of YbB$_6$, a proposed topological insulator candidate with moderate correlation. The in-situ cleaved sample surface has two dominant morphologies: atomic square lattices and disordered rows, which likely correspond to Yb and B terminations, respectively. Spatially resolved $dI/dV$ maps show enhanced tunneling due to the local perturbation of the tip-induced band bending. The $dI/dV$ spectra reveal a bulk gap with distinct in-gap features near the Fermi level on different terminations. Our study presents nanoscale evidence for the interplay between surface structure, correlation and topological properties.

*The work at Harvard was supported by NSF-DMR-1410480 and NSERC (ZHZ).

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Authors

  • Zhihuai Zhu

    • Department of Physics, Harvard University, Cambridge, MA 02138, USA

  • Y. He

    • Department of Physics, Harvard University, Cambridge, MA 02138, USA

  • D.-J. Kim

    • Department of Physics and Astronomy, University of California, Irvine, California 92697, USA

  • Z. Fisk

    • Department of Physics and Astronomy, University of California, Irvine, California 92697, USA

  • J. E. Hoffman

    • Department of Physics, Harvard University, Cambridge, MA 02138, USA