Imaging emergent heavy Dirac fermions of a topological Kondo insulator

Abstract

Kondo insulators are primary candidates in the search for strongly correlated topological quantum phases, which may host topological order, fractionalization, and non-Abelian statistics. Within some Kondo insulators, the hybridization gap is predicted to protect a nontrivial topological invariant and to harbor emergent heavy Dirac fermion surface modes. We use high-energy-resolution spectroscopic imaging in real and momentum space on the Kondo insulator, SmB${}_6$. On cooling through $T_{\Delta }^{\ast }\approx$ 35 K we observe the opening of an insulating gap that expands to $\Delta \approx$ 10 meV at 2 K. Within the gap, we image the formation of linearly dispersing surface states with effective masses reaching $m^{\ast }=(410\pm 20)m_e$. We thus demonstrate existence of a strongly correlated topological Kondo insulator phase hosting the heaviest known Dirac fermions.

References in corpus (35)

• Topological Kondo Insulators
• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Correlated Topological Insulators with Mixed Valence
• Topological surface state in the Kondo Insulator Samarium Hexaboride
• Quantum oscillations in Kondo Insulator SmB${}_6$
• Robust Surface Hall Effect and Nonlocal Transport in SmB6: Indication for an Ideal Topological Insulator
• Topological Kondo Insulators
• Observation of in-gap surface states in the Kondo insulator SmB6 by photoemission
• Unconventional Fermi surface in an insulating state
• Imaging the Fano Lattice to 'Hidden Order' Transition in URu2Si2
• Visualizing heavy fermions emerging in a quantum critical Kondo lattice
• Imaging Cooper Pairing of Heavy Fermions in CeCoIn5
• Cubic Topological Kondo Insulators
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Symmetry Enforced Non-Abelian Topological Order at the Surface of a Topological Insulator
• Gapped Symmetry Preserving Surface-State for the Electron Topological Insulator
• Polarity-driven surface metallicity in SmB${}_6$
• Tuning bulk and surface conduction in topological Kondo insulator SmB6
• Hybridization gap and Fano resonance in SmB${}_6$
• Electron Cotunneling into a Kondo Lattice
• Emergence of a coherent in-gap state in SmB6 Kondo insulator revealed by scanning tunneling spectroscopy
• Differential Conductance and Quantum Interference in Kondo Systems
• One-dimensional edge state transport in a topological Kondo insulator
• Samarium hexaboride: A trivial surface conductor
• Theory of quasiparticle interference on the surface of a strong topological insulator
• Additional energy scale in SmB${}_6$ at low temperature
• Exotic Kondo crossover in a wide temperature region in the topological Kondo insulator SmB6 revealed by high-resolution ARPES
• Heavy surface state in a possible topological Kondo insulator: Magneto-thermoelectric transport on the (011)-plane of SmB${}_6$
• Magnetic Instability on the Surface of Topological Insulators
• Defects in Heavy-Fermion Materials: Unveiling Strong Correlations in Real Space
• Consistency between ARPES and STM measurements on SmB${}_6$
• Fractionalized Fermi liquid on the surface of a topological Kondo insulator
• A Strongly-Interacting Dirac Liquid on the Surface of a Topological Kondo Insulator
• Quantum spin fluctuations in the bulk insulating state of pure and Fe-doped SmB6
• Identifying Collective Modes via Impurities in the Cuprate Superconductors

Cited by in corpus (32)

• Flat bands, strange metals, and the Kondo effect
• Probing topological quantum matter with scanning tunnelling microscopy
• Consistency between ARPES and STM measurements on SmB${}_6$
• Visualizing the atomic-scale origin of metallic behavior in Kondo insulators
• Quantum-well states at the surface of the heavy-fermion superconductor URu${}_2$Si${}_2$
• Critical role of magnetic moments in heavy-fermion materials: revisiting mysteries of SmB${}_6$
• Definitive Surface Magnetotransport Study of SmB${}_6$
• Hall anomaly, Quantum Oscillations and Possible Lifshitz Transitions in Kondo Insulator YbB${}_{12}$: Evidence for Unconventional Charge Transport
• Tuning the topological character of half-Heusler systems: A comparative study on Y$T$Bi ($T$ = Pd, Pt)
• Realization of Kagome Kondo lattice
• Kondo quasiparticle dynamics observed by resonant inelastic x-ray scattering
• Bulk transport paths through defects in floating zone and Al flux grown SmB${}_6$
• Spin-selective tunneling from nanowires of the candidate topological Kondo insulator SmB6
• A microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn${}_3$
• Spin-polarized imaging of strongly interacting fermions in the ferrimagnetic state of Weyl candidate CeBi
• Topological zero modes and correlation pumping in an engineered Kondo lattice
• Correlated Topological Mixed-Valence Insulators in Moiré Hetero-Bilayers
• How to identify and characterize strongly correlated topological semimetals
• Comparative Scanning Tunneling Microscopy Study on Hexaborides
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Realizing a topological diode effect on the surface of a topological Kondo insulator
• Microwave Meissner Screening of Proximity coupled Topological Insulator / Superconductor Bilayers
• Low-energy excitations and transport functions of the one-dimensional Kondo insulator
• Phase stability in SmB${}_6$
• Surface excitations relaxation in the Kondo insulator Sm${}_{1-x}$Gd${}_x$B${}_6$
• Switching on surface conduction in a topological insulator
• Observation of the superconducting proximity effect from surface states in SmB${}_6$/YB${}_6$ thin film heterostructures via terahertz spectroscopy
• Mapping out the emergence of topological features in the highly alloyed topological Kondo insulators Sm${}_{1-x}{M}_x$B${}_6$ ($M$=Eu, Ce)
• Persistence of correlation-driven surface states in SmB6 under pressure
• Candidate entanglement invariants for two Dirac spinors
• Low degree Lorentz invariant polynomials as potential entanglement invariants for multiple Dirac spinors
• Nanoscale Conducting and Insulating Domains on YbB${}_6$