Probing the superconducting gap structure of ScRuSi via $\mu$SR and first-principles calculations

Abstract

In this study, we present a thorough investigation into the superconducting state of the ruthenium-based ternary equiatomic compound ScRuSi. Our analysis combines experimental techniques, including muon spin rotation/relaxation ($\mu$SR) and low-temperature resistivity measurements, with theoretical insights derived from first-principles calculations. The low-temperature resistivity measurements reveal a distinct superconducting phase transition in the orthorhombic structure of ScRuSi at a critical temperature ($T_{\text{C}}$) of $2.5$ K. Further, the TF-$\mu$SR analysis yields a gap-to-critical-temperature ratio of $2\Delta /k_{\mathrm{B}}{T}_{\mathrm{C}}=2.71$, a value consistent with results obtained from previous heat capacity measurements. The temperature dependence of the superconducting normalized depolarization rate is fully described by the isotropic $s$-wave gap model. Additionally, zero-field $\mu$SR measurements indicate that the relaxation rate remains nearly identical below and above $T_{\text{C}}$. This observation strongly suggests the preservation of time-reversal symmetry within the superconducting state. By employing the McMillan-Allen-Dynes equation, we calculate a $T_{\text{C}}$ of $2.11$ K from first-principles calculations within the density functional theory framework. This calculated value aligns closely with the experimentally determined critical temperature. The coupling between the low-frequency phonon modes and the transition metal d-orbital states play an important role in governing the superconducting pairing in ScRuSi. The combination of experimental and theoretical approaches provides a comprehensive microscopic understanding of the superconducting nature of ScRuSi, offering insights into its critical temperature, pairing symmetry, and the underlying electron-phonon coupling mechanism.

10 pages, 7 figures

References in corpus (12)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Quantum ESPRESSO toward the exascale
• Magnetic Penetration Depth in Unconventional Superconductors
• Origin of superconductivity and latent charge density wave in NbS${}_2$
• Superconductivity in intercalated group-IV honeycomb structures
• Probing the superconducting gap structure in the noncentrosymmetric topological superconductor ZrRuAs
• Time-Reversal Symmetry Breaking Superconductivity in Three-Dimensional Dirac Semimetallic Silicides
• Probing the superconducting ground state of ZrIrSi: A $\mu$SR study
• Superconductivity at 3.1 K in the orthorhombic ternary silicide ScRuSi
• Possible multiband superconductivity in the quaternary carbide YRe2SiC
• Time reversal symmetry breaking and s-wave superconductivity in CaPd2Ge2: A $\mu$SR study
• Exploring Superconductivity in Ba${}_3$Ir${}_4$Ge${}_{16}$: Experimental and Theoretical Insights