Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 85: Topology: Majorana Physics II

TT 85.7: Vortrag

Freitag, 22. März 2024, 11:15–11:30, H 3005

Exploration of topological states and multiple gaps in MgB₂ superconductors — •Nora Kucska¹, Andras Laszloffy¹, Laszlo Szunyogh², and Balazs Ujfalussy¹ — ¹HUN-REN Wigner Research Centre for Physics, Budapest, Hungary — ²Budapest University of Technology and Economics, Budapest, Hungary

Unfortunately, most known topological superconductors possess low transition temperatures, impeding the experimental observation of Majorana fermions. MgB₂, a widely recognized high-temperature superconductor would consequently be an ideal subject to study due to the suspected topological properties of its band structure. This gives light to its intriguing quantum phase characterized by protected gapless surface/edge states within a bulk superconducting gap, possibly hosting Majorana fermions.

Using fully relativistic first-principles calculations, a Dirac-nodal line structure is investigated through the bulk and surface band structure of MgB₂. Adding magnetic impurities to the surface, the interaction between the topological system with the impurities is explored.

MgB₂ is also known for having multiple gaps in the superconducting state. Numerous experimental and theoretical studies find either one or two distinct gaps in the density of states, while a third gap was found in thin films of MgB₂ and by theoretical non-relativistic ab initio calculations. The multiple gap structure of MgB₂ was analyzed giving more insights on the topic. We study the so-called Yu-Shiba-Rusinov states in the context of this multi gapped superconductor.

Keywords: first principle calculations; topological superconductors; multiple gaps; magnetic impurities