Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

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

TT: Fachverband Tiefe Temperaturen

TT 17: Poster Session Correlated Electrons 1

TT 17.6: Poster

Montag, 16. März 2020, 15:00–19:00, P2/EG

Optical Spectroscopy of CeRh₂As₂ and LaRh₂As₂ — Shin-ichi Kimura^1,2, Seunghyun Khim³, and •Jörg Sichelschmidt³ — ¹Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan — ²Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan — ³Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

CeRh₂As₂ is a new heavy-fermion superconductor (T_C≃ 0.25 K) which crystallizes in the CaBe₂Ge₂-type structure where inversion symmetry is locally broken at the Ce site. It is discussed to be a model system to investigate the influence of Rashba-type interactions on heavy-fermion superconductivity. We present results of optical reflectivity on CeRh₂As₂ and LaRh₂As₂ for temperatures down to 10 K. In the far-infrared energy region CeRh₂As₂ shows a strong spectral weight redistribution with decreasing temperature which is a typical feature found in heavy-fermion materials. The spectra of LaRh₂As₂ show an unexpected strong temperature dependence which has not been observed in other counterparts of heavy-fermion materials. The phonon peaks of both compounds show unusually strong softening. Furthermore, the phonon frequency is higher in the Ce-system than in the La-system, in contrast to expectation. We discuss these observations in terms of the lack of local inversion symmetry in the crystal structure.