Superconducting Gap Structure of Filled Skutterudite LaOs${}_4$As${}_{12}$ Compound through $\mu$SR Investigations

Abstract

Filled skutterudite compounds have gained attention recently as an innovative platforms for studying intriguing low-temperature superconducting properties. Regarding the symmetry of the superconducting gap, contradicting findings from several experiments have been made for LaRu${}_4$As${}_{12}$ and its isoelectronic counterpart, LaOs${}_4$As${}_{12}$. In this vein, we report comprehensive bulk and microscopic results on LaOs${}_4$As${}_{12}$ utilizing specific heat analysis and muon-spin rotation/relaxation ($\mu$SR) measurements. Bulk superconductivity with $T_C$ = 3.2 K was confirmed by heat capacity. The superconducting ground state of the filled-skutterudite LaOs${}_4$As${}_{12}$ compound is found to have two key characteristics: superfluid density exhibits saturation type behavior at low temperature, which points to a fully gapped superconductivity with gap value of $2\Delta /k_B{T}_C$ = 3.26; additionally, the superconducting state does not show any sign of spontaneous magnetic field, supporting the preservation of time-reversal symmetry. These results open the door for the development of La-based skutterudites as special probes for examining the interplay of single- and multiband superconductivity in classical electron-phonon systems.

5 pages, 4 figures

References in corpus (5)

• Magnetic Penetration Depth in Unconventional Superconductors
• Multiband superconductivity in PrPt4Ge12 single crystals
• The filled skutterudite CeOs${}_4$As${}_{12}$: a hybridization gap semiconductor
• Probing the superconducting ground state of ZrIrSi: A $\mu$SR study
• Multigap Superconductivity in the Filled-Skutterudite Compound LaRu${}_4$As${}_{12}$ probed by muon spin rotation

Cited by in corpus (1)

• A-15 type superconducting hydride $L{a}_4{H}_{23}$: Nanograined structure with low strain, strong electron-phonon interaction, and moderate level of nonadiabaticity