Irreversible proliferation of magnetic moments at cleaved surfaces of the topological Kondo insulator SmB6

Abstract

The compound SmB${}_6$ is the best established realization of a topological Kondo insulator, in which a topological insulator state is obtained through Kondo coherence. Recent studies have found evidence that the surface of SmB${}_6$ hosts ferromagnetic domains, creating an intrinsic platform for unidirectional ballistic transport at the domain boundaries. Here, surface-sensitive X-ray absorption (XAS) and bulk-sensitive resonant inelastic X-ray scattering (RIXS) spectra are measured at the Sm N${}_{4,5}$-edge, and used to evaluate electronic symmetries, excitations and temperature dependence near the surface of cleaved samples. The XAS data show that the density of large-moment atomic multiplet states on a cleaved surface grows irreversibly over time, to a degree that likely exceeds a related change that has recently been observed in the surface 4f orbital occupation.

References in corpus (7)

• Correlated Topological Insulators with Mixed Valence
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Exotic Kondo crossover in a wide temperature region in the topological Kondo insulator SmB6 revealed by high-resolution ARPES
• Multiplet resonance lifetimes in resonant inelastic X-ray scattering involving shallow core levels
• Experimental signatures of phase interference and sub-femtosecond time dynamics on the incident energy axis of resonant inelastic X-ray scattering
• Charge transfer excitations in VUV and soft X-ray resonant scattering spectroscopies
• From bad metal to Kondo insulator: temperature evolution of the optical properties of SmB${}_6$

Cited by in corpus (1)

• Phase stability in SmB${}_6$