Bulk and surface electronic properties of SmB6: a hard x-ray photoelectron spectroscopy study

Abstract

We have carried out bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES) measurements on in-situ cleaved and ex-situ polished SmB6 single crystals. Using the multiplet-structure in the Sm 3d core level spectra, we determined reliably that the valence of Sm in bulk SmB6 is close to 2.55 at ~5 K. Temperature dependent measurements revealed that the Sm valence gradually increases to 2.64 at 300 K. From a detailed line shape analysis we can clearly observe that not only the J=0 but also the J=1 state of the Sm 4f 6 configuration becomes occupied at elevated temperatures. Making use of the polarization dependence, we were able to identify and extract the Sm 4f spectral weight of the bulk material. Finally, we revealed that the oxidized or chemically damaged surface region of the ex-situ polished SmB6 single crystal is surprisingly thin, about 1 nm only.

arXiv comment11 pages, 8 figures

References in corpus (29)

• Topological Kondo Insulators
• Multiplet ligand-field theory using Wannier orbitals
• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Low-temperature surface conduction in the Kondo insulator SmB${}_6$
• Correlated Topological Insulators with Mixed Valence
• Topological surface state in the Kondo Insulator Samarium Hexaboride
• Robust Surface Hall Effect and Nonlocal Transport in SmB6: Indication for an Ideal Topological Insulator
• Observation of in-gap surface states in the Kondo insulator SmB6 by photoemission
• A theory of Topological Kondo Insulators
• Surface and Bulk Electronic Structure of the Strongly Correlated System SmB${}_6$ and Implications for a Topological Kondo Insulator
• Cubic Topological Kondo Insulators
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Polarity-driven surface metallicity in SmB${}_6$
• Hybridization gap and Fano resonance in SmB${}_6$
• Emergence of a coherent in-gap state in SmB6 Kondo insulator revealed by scanning tunneling spectroscopy
• One-dimensional edge state transport in a topological Kondo insulator
• Additional energy scale in SmB${}_6$ at low temperature
• Weak Antilocalization and Linear Magnetoresistance in The Surface State of SmB6
• The energy gap of intermediate-valent SmB6 studied by point-contact spectroscopy
• Exotic Kondo crossover in a wide temperature region in the topological Kondo insulator SmB6 revealed by high-resolution ARPES
• SmB6 Photoemission: Past and Present
• Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields
• Magnetotransport Measurements of the Surface States of Samarium Hexaboride using Corbino Structures
• Pressure-resistant intermediate valence in Kondo insulator SmB6
• A new exotic state in an old material: A tale of Samarium Hexaboride
• Surface and electronic structure of SmB${}_6$ through Scanning Tunneling Microscopy
• Valence Characterization of Surface and Subsurface Region in SmB6
• SmO thin films: a flexible route to correlated flat bands with nontrivial topology
• Quantum phase transition and destruction of Kondo effect in pressurized SmB6

Cited by in corpus (18)

• Quantum Oscillations of Electrical Resistivity in an Insulator
• Unconventional thermal metallic state of charge-neutral fermions in an insulator
• 4$f$ crystal field ground state of the strongly correlated topological insulator SmB${}_6$
• Chemical and valence reconstruction at the surface of SmB6 revealed with resonant soft x-ray reflectometry
• Diamagnetic Sm${}^{3+}$ in the topological Kondo insulator SmB${}_6$
• A RIXS investigation of the crystal-field splitting of Sm${}^{3+}$ in SmB${}_6$
• Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film
• Comparative Scanning Tunneling Microscopy Study on Hexaborides
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Hard x-ray photoemission study on strain effect in LaNiO${}_3$ thin films
• Phase stability in SmB${}_6$
• 4$f$ electron temperature driven ultrafast electron localization
• Persistence of correlation-driven surface states in SmB6 under pressure
• Importance of orbital fluctuations for the magnetic dynamics in heavy-fermion compound SmB${}_6$
• f-electron charge densities probed using core level non-resonant inelastic x-ray scattering
• Optical and magnetic excitations in the underscreened quasi-quartet Kondo lattice
• Direct measurement of a remnant Fermi surface in SmB6
• Anomalous 4$f$ fine structure in TmSe${}_{1-x}$Te${}_x$ across the metal-insulator transition