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  • Letter
  • Open Access

Surface orbital order and chemical potential inhomogeneity of the iron-based superconductor FeTe0.55Se0.45 investigated with special STM tips

Dongfei Wang1,*, Ruidan Zhong2,†, Genda Gu2, and Roland Wiesendanger1,‡

  • 1Department of Physics, University of Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
  • 2Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA

  • *dwang@physnet.uni-hamburg.de
  • †Present address: Tsung-Dao Lee Institute and School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
  • ‡wiesendanger@physnet.uni-hamburg.de
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Phys. Rev. Research 3, L032055 – Published 27 August, 2021

DOI: https://doi.org/10.1103/PhysRevResearch.3.L032055

Abstract

The atomically clean surface of the iron-based superconductor FeTe0.55Se0.45 is investigated by low-temperature scanning tunneling microscope (STM) with different tip apex states. We show that the scattering channel between the Γ and X/Y points of the sample's Brillouin zone can be visualized clearly by a supersharp STM tip. Furthermore, by manipulating a single Fe atom onto the tip apex, signatures of the orbital nature of the subsurface Fe layer of FeTe0.55Se0.45 can be identified. By preparing a charged tip state, the intrinsic spatial inhomogeneity of the chemical potential of FeTe0.55Se0.45 can be revealed. As a result, three different types of vortex bound states originating from locally varying topological properties of the FeTe0.55Se0.45 surface are observed by scanning tunneling spectroscopy.

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Outline

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Phys. Rev. Research 3, L032055– Published 27 August, 2021
  • Received 15 April 2021
  • Revised 29 June 2021
  • Accepted 3 August 2021
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