Probing the interlayer coupling in 2$H$-NbS${}_2$ via soft x-ray angle-resolved photoemission spectroscopy

Abstract

In the large family of two-dimensional (2D) layered materials including graphene, its honeycomb analogs, and transition-metal dichalcogenides, the interlayer coupling plays a rather intriguing role. On the one hand, the weak van der Waals interaction that holds the layers together endows these compounds with quasi-2D properties, which might imply small interlayer effects on the electronically active bands. On the other hand, the oft-witnessed differences in electronic, optical, and magnetic behaviors of monolayers, bilayers, and multilayers of the same compound must have as their microscopic origin the detailed interlayer hopping parameters. Given the few experimental reports that have attempted to explicitly extract these parameters, we employ soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) to probe the interlayer coupling in superconducting 2$H$-NbS${}_2$. We visualize the S 3$p_z$ bands that disperse with respect to the out-of-plane momentum and introduce a simple tight-binding model to extract the interlayer hopping parameters. From first-principles calculations, we clarify how atomic distances and the proper accounting for screening via hybrid functionals influence these bands. The knowledge of interlayer hopping parameters is particularly pertinent in NbS${}_2$, where recent experiments have uncovered fingerprints of finite-momentum superconductivity in the bulk material and heterostructures.

10 pages, 5 figures + SM

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Cited by in corpus (6)

• Darkness in interlayer and charge density wave states of 2H-TaS2
• MPd5 kagome superconductors studied by density functional calculations
• Investigating the superconducting state of 2$H$-NbS${}_2$ as seen by the vortex lattice
• From orbital to paramagnetic pair breaking in layered superconductor 2H-NbS${}_2$
• Emergent 3D Fermiology and Magnetism in an Intercalated Van der Waals System
• Photoemission angular distribution beyond the single wavevector description of photoelectron final states