Regensburg 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 37: Correlated Electrons: Poster

TT 37.6: Poster

Wednesday, March 19, 2025, 15:00–18:00, P4

Cyclotron Resonance on SmB₆ Probed by Superconducting Coplanar Microwave Resonators — •Anastasia Bauernfeind and Marc Scheffler — 1. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany

Samarium hexaboride (SmB₆) is a homogeneously mixed-valent, narrow-gap semiconductor typically classified as a topological Kondo insulator. Its resistivity increases sharply as the temperature decreases, showing activated behavior that saturates below approximately 5 K. Experimental evidence suggests that topological surface states dominate low-temperature transport. Two notable studies on quantum oscillations in SmB₆ have sparked intense debate about their origin: one observes behavior consistent with a two-dimensional (2D) Fermi surface attributed to surface states, while the other reports a three-dimensional (3D) bulk Fermi surface, despite the insulating nature of the bulk at low temperatures. In our research, we perform cyclotron resonance experiments on SmB₆ using superconducting coplanar waveguides, a powerful method for investigating the Fermi surface of various materials. By tracing the evolution of the cyclotron frequency (up to 20 GHz) as a function of magnetic field, we can determine the type of charge carriers, the effective mass, and the properties of the associated electronic bands. Combined with temperature-dependent measurements (down to 20 mK) and power-dependent studies, this approach provides valuable insights into the electronic structure of the strongly correlated material SmB₆.

Keywords: Kondo insulators; Topological insulators; Cyclotron Resonance; Quantum oscillations; Superconducting resonators