Fermi surface investigation of the filled skutterudite LaRu4As12

Symmetry of Order Parameters in Multiband Superconductors LaRu4As12 and PrO

“…2(a The fact that, in all these cases, we observe similar enhancements at essentially the same temperature is in consistence with a negligible lattice anisotropy of LaRu 4 As 12 [30]. An irrelevance of anisotropy effects to the sudden enhancement in H c1 ðTÞ is additionally underlined by the fact that the isostructural compounds PrRu 4 As 12 (T c ¼ 2.3 K) and LaOs 4 As 12 (T c ¼ 3.2 K) with the similar Fermi-surface (FS) topologies [32,33] display no anomalies down to at least 0.12T c and 0.17T c , respectively [Fig. 2(b)].…”

“…However, when comparing to other La-filled skutterudites, one notes a general similarity of their FSs and only slight differences reflect various electrostatic potentials and internal positions of the T and Pn atoms. In fact, a detailed Fermi-surface investigation of LaRu 4 As 12 by means of de Haas-van Alphen measurements and density-functionaltheory calculations also showed a nearly spherical sheet centered at the Γ point and a multiply connected threedimensional FS sheet [33]. This indicates that multigap superconductivity in LaRu 4 As 12 emerges for a different reason as in MgB 2 (different dimensionality of two bands) or iron-based superconductors (appearance of multiple Fermi-surface pockets).…”

“…Single crystals of the As-based filled skutterudites were grown by mineralization in a molten Cd:As flux [31]. Strong de Haas-van Alphen signals obtained from similarly prepared crystals attest to their high quality [32,33]. PrOs 4 Sb 12 single crystals were grown from an Sb flux following the method described in Ref.…”

Multigap superconductivity in the filled-skutterudite compound LaRu4As12 probed by muon spin rotation

“…This enhancement is even more intriguing if one takes into account that LaRu 4 As 12 does not show any distinct differences in both the conduction electron density of states at the Fermi level and the vibrational properties [36,37]. Another remarkable feature of LaRu 4 As 12 is that it has several arguments for multiband superconductivity [1][2][3][4][5]33,36]. Specifically, the temperature dependence of the lower critical field H c1 displays a sharp anomaly deep in the superconducting state, indicative of a rarely observed case of almost decoupled bands [33].…”

“…These parameters are substantially enhanced compared to the sister compounds LaOs 4 As 12 [34] and PrRu 4 As 12 [35], with T c = 3.2 and 2.3 K, respectively. This enhancement is even more intriguing if one takes into account that LaRu 4 As 12 does not show any distinct differences in both the conduction electron density of states at the Fermi level and the vibrational properties [36,37]. Another remarkable feature of LaRu 4 As 12 is that it has several arguments for multiband superconductivity [1][2][3][4][5]33,36].…”