Probing the superconducting ground state of on non-centrosymmetric Ising superconductor 4H-NbSe2

This muon spin rotation (µSR) proposal aims to investigate the unconventional superconducting properties of the non-centrosymmetric superconductor 4H-NbSe2, which exhibits superconductivity at a critical temperature (Tc) of 6.21 K. Temperature-dependent magnetization and resistivity measurements have revealed a significantly higher upper critical field (Hc2) for in-plane fields (32.9 T) compared to out-of-plane fields (5.77 mT), suggesting the possibility of Ising superconductivity in this compound. First-principles calculations further support this notion by confirming a similar electronic structure and spin-orbit coupling strength as the monolayer polymorph. Given the challenges associated with local measurements in monolayers and the existing ambiguity regarding the superconducting ground state (spin-triplet vs. Ising), bulk 4H-NbSe2 presents a unique opportunity to explore the superconducting ground state through µSR for this potential Ising superconductor.