Dresden 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 2: Electronic structure of surfaces: Spectroscopy, surface states I
O 2.3: Invited Talk
Monday, March 9, 2026, 11:00–11:30, HSZ/0201
Superconducting Fermi arcs. — •Andrii Kuibarov, Susmita Changdar, Oleksandr Suvorov, Luminita Harnagea, Bernd Büchner, and Sergey Borisenko — Leibnitz Institute for Solid State and Materials Research, Dresden, Germany
PtBi2 is a trigonal non-centrosymmetric material that has recently drawn attention as a natural platform for topological superconductivity, without the need for engineered heterostructures. Recent STM studies have strengthened this claim by showing a superconducting gap with size up to 20 meV and critical temperature around 45 K.
Using angle-resolved photoemission spectroscopy, we demonstrate that both terminations of PtBi2 expose Fermi arc surface states, which become superconducting at approximately 15 K with a gap size up to 3 meV, while the bulk of the material remains metallic, making PtBi2 a surface-only superconductor. Further momentum-resolved gap measurements have shown that the superconducting gap on the Fermi arcs is anisotropic, with the superconducting node located in the center of six Fermi arcs, making it the first i-wave (l = 6) superconductor. This anisotropy implies the formation of Majorana surface cones and predicts robust zero-energy flat-band Majorana states at the hinges of the crystal.
Keywords: topology; tuperconductivity; ARPES; Weyl semimetal; photoemission