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TT: Fachverband Tiefe Temperaturen
TT 24: Unconventional Superconductors
TT 24.8: Vortrag
Mittwoch, 19. März 2025, 12:00–12:15, H31
Topological Fermi Arcs and Surface Superconductivity in PtBi2 — •Julia Besproswanny1, Sebastian Schimmel1, Sven Hoffmann1, Gregory Shipunov2, Saicharan Aswartham2, Joaquin Puig3, Yanina Fasano3, Danny Baumann2, Ricardo Vocaturo2, Jorge I. Facio3, Oleg Jansen2, Jeroen van den Brink2, Bernd Büchner2, and Christian Hess1 — 1University of Wuppertal, 42119 Wuppertal, Germany — 2IFW Dresden, 01069 Dresden, Germany — 3Centro Atómico Bariloche, Instituto Balseiro, 8400 Bariloche, Argentina
t-PtBi2 is a topological Weyl semimetal, as evidenced by band structure and quasiparticle interference (QPI) investigations [1]. It also exhibits unconventional surface superconductivity [2,3], with ARPES revealing a superconducting energy gap only on the Fermi arc states [3]. Low-temperature scanning tunneling microscopy and spectroscopy (STM/STS) reveals locally varying sample-dependent superconductivity revealed by the energy gap. In some cases the scale of the gap suggests BCS critical temperatures as high as 70-130 K. We study the temperature and magnetic field dependence of the the energy gap, demonstrating its persistence up to 50 K. Furthermore, QPI measurements in the superconducting state indicate an interplay between topological Fermi arcs and superconductivity.
[1] S. Hoffmann et. al., Adv. Phys. Res. 2400150 (2024);
[2] S. Schimmel et. al., Nat. Commun. 15, 9895 (2024);
[3] A. Kuibarov et. al., Nature 626, 294(2024).
Keywords: Scanning tunneling microscopy; superconductivity; topology; Wyl semimetal; topological superconductivity