Work

Transport signatures of incipient orbital Fulde-Ferrell-Larkin-Ovchinnikov state in 2 H − NbS 2 flakes

Year: 2025

Type: article

Abstract: Symmetry breaking in a layered superconductor with Ising spin-orbit coupling has offered an opportunity to realize unconventional superconductivity. To be more specific, an orbital Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, exhibiting layer-dependent finite-momentum pairing, may emerge in transition metal dichalcogenides materials (TMDC) in the presence of an in-plane magnetic field. Orbital FFLO states can be more robust against the magnetic field than the conventional superconducting state with zero-momentum pairing. This feature renders its potential in field-resilient superconducting functionality. Although an orbital FFLO state has been reported in ${\mathrm{NbSe}}_{2}$ and ${\mathrm{MoS}}_{2}$, it is not yet clear if an orbital FFLO state can be extended to other TMDC superconductors. Here, we report the transport signature of incipient orbital FFLO state in $2H\ensuremath{-}{\mathrm{NbS}}_{2}$ flakes and its dependence on the thickness of flakes. We conclude that the relatively weak interlayer coupling is instrumental in stabilizing orbital FFLO state at higher temperature with respect to the critical temperature and lower magnetic field with respect to paramagnetic limit in ${\mathrm{NbS}}_{2}$ in comparison to its ${\mathrm{NbSe}}_{2}$ counterpart.

Source: Physical review. B./Physical review. B

DOI: 10.1103/m871-4mbq