Electronic structures and surface reconstructions in magnetic superconductor RbEuFe4As4

DOI: 10.1021/acs.jpclett.0c02711

Authors: Vasily S. Stolyarov (Dukhov Research Institute of Automatics (VNIIA)) , Kirill S. Pervakov (Lebedev Physical Institute) , Anna S. Astrakhantseva (Moscow Institute of Physics and Technology) , Igor A. Golovchanskiy (Moscow Institute of Physics and Technology; National University of Science and Technology MISIS) , Denis V. Vyalikh (Donostia International Physics Center (DIPC); IKERBASQUE, Basque Foundation for Science) , Timur K. Kim (Diamond Light Source) , Sergey V. Eremeev (Institute of Strength Physics and Materials Science, Russian Academy of Sciences) , Vladimir A. Vlasenko (Lebedev Physical Institute) , Vladimir M. Pudalov (Lebedev Physical Institute) , Alexander A. Golubov (Moscow Institute of Physics and Technology; Institute of Nanotechnology, The Netherlands) , Eugene V. Chulkov (Donostia International Physics Center (DIPC); National Research University Higher School of Economics) , Dimitri Roditchev (LPEM, UMR-8213, ESPCI-Paris, PSL, CNRS, Sorbonne University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry Letters

State: Published (Approved)
Published: October 2020

Abstract: In pnictide RbEuFe4As4, superconductivity sets in at 36 K and coexists, below 15–19 K, with the long-range magnetic ordering of Eu 4f spins. Here we report scanning tunneling experiments performed on cold-cleaved single crystals of the compound. The data revealed the coexistence of large Rb-terminated and small Eu-terminated terraces, both manifesting 1 × 2 and 2‾√×2‾√ 2 × 2 reconstructions. On 2‾√×2‾√ 2 × 2 surfaces, a hidden electronic order with a period ∼5 nm was discovered. A superconducting gap of ∼7 meV was seen to be strongly filled with quasiparticle states. The tunneling spectra compared with density functional theory calculations confirmed that flat electronic bands due to Eu 4f orbitals are situated ∼1.8 eV below the Fermi level and thus do not contribute directly to Cooper pair formation.

Journal Keywords: Tunneling; Scanning tunneling spectroscopy; Superconductivity; Order; Scanning tunneling microscopy

Subject Areas: Materials, Physics, Chemistry


Technical Areas:

Added On: 26/10/2020 08:58

Discipline Tags:

Superconductors Quantum Materials Hard condensed matter - electronic properties Physics Physical Chemistry Chemistry Magnetism Materials Science

Technical Tags: