Dirac mass generation from crystal symmetry breaking on the surfaces of topological crystalline insulators

Abstract

The tunability of topological surface states (SS) and controllable opening of the Dirac gap are of fundamental and practical interest in the field of topological materials. In topological crystalline insulators (TCIs), a spontaneously generated Dirac gap was recently observed, which was ascribed to broken cubic crystal symmetry. However, this structural distortion has not been directly observed so far, and the microscopic mechanism of Dirac gap opening via crystal symmetry breaking remains elusive. In this work, we present scanning tunneling microscopy (STM) measurements of a TCI Pb${}_{1-x}$Sn${}_x$Se for a wide range of alloy compositions spanning the topological and non-topological regimes. STM topographies directly reveal a symmetry-breaking distortion on the surface, which imparts mass to the otherwise massless Dirac electrons - a mechanism analogous to the long sought-after Higgs mechanism in particle physics. Remarkably, our measurements show that the Dirac gap scales with alloy composition, while the magnitude of the distortion remains nearly constant. Based on theoretical calculations, we find the Dirac mass is controlled by the composition-dependent SS penetration depth, which determines the weight of SS in the distorted region that is confined to the surface. Finally, we discover the existence of SS in the non-topological regime, which have the characteristics of gapped, double-branched Dirac fermions.

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• Topological Insulators
• Topological insulators and superconductors
• Topological Insulators in Three Dimensions
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Topological Crystalline Insulators
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Topological Crystalline Insulators in the SnTe Material Class
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Experimental realization of a topological crystalline insulator in SnTe
• Topological crystalline insulator states in Pb(1-x)Sn(x)Se
• A topological crystalline insulator (TCI) phase via topological phase transition and crystalline mirror symmetry
• Intra-unit-cell electronic nematicity of the high-Tc copper-oxide pseudogap states
• Observation of Landau levels of Dirac fermions in graphite
• Anomalous Finite Size Effects on Surface States in the Topological Insulator Bi${}_2$Se${}_3$
• Observation of Dirac node formation and mass acquisition in a topological crystalline insulator
• Momentum-Resolved Landau-Level Spectroscopy of Dirac Surface State in Bi2Se3
• Surface States of Topological Crystalline Insulators in IV-VI Semiconductors
• The Quantum Hall Transition in Real Space: From Localized to Extended States
• Tunability of the k-space Location of the Dirac Cones in the Topological Crystalline Insulator Pb1-xSnxTe
• Experimental observation of Dirac-like surface states and topological phase transition in Pb${}_{1-x}$Sn${}_x$Te(111) films
• Symmetry breaking and Landau quantization in topological crystalline insulators
• Mapping the unconventional orbital texture in topological crystalline insulators
• Spin-polarized (001) surface states of the topological crystalline insulator Pb_{0.73}Sn_{0.27}Se
• STM imaging of symmetry-breaking structural distortion in the Bi-based cuprate superconductors
• Quasiparticle Interference on the Surface of Topological Crystalline Insulator Pb(1-x)Sn(x)Se
• Imaging the Nanoscale Band Structure of Topological Sb

Cited by in corpus (62)

• Weyl and Dirac Semimetals in Three Dimensional Solids
• Colloquium: Topological Band Theory
• Probing topological quantum matter with scanning tunnelling microscopy
• Crystal Field Effect Induced Topological Crystalline Insulators In Monolayer IV-VI Semiconductors
• Robust spin-polarized midgap states at step edges of topological crystalline insulators
• Theory of interacting topological crystalline insulators
• Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation
• Superconductivity in doped Dirac semimetals
• Topo-fermiology
• Direct observation and temperature control of the surface Dirac gap in the topological crystalline insulator (Pb,Sn)Se
• Electrically Tunable Quantum Spin Hall State in Topological Crystalline Insulator Thin films
• Anomalous Crystal Symmetry Fractionalization on the Surface of Topological Crystalline Insulators
• Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
• Modern theory of magnetic breakdown
• Interplay of orbital effects and nanoscale strain in topological crystalline insulators
• Topological phase diagram and saddle point singularity in a tunable topological crystalline insulator
• Surface electronic state of superconducting topological crystalline insulator
• Weak-link Josephson Junctions Made from Topological Crystalline Insulators
• Surface oxidation and thermoelectric properties of indium-doped tin telluride nanowires
• Broken mirror symmetry tuned topological transport in PbTe/SnTe heterostructures
• Mass acquisition of Dirac fermions in Cr-doped topological insulator Sb2Te3 films
• Unexpected superconductivity at nanoscale junctions made on the topological crystalline insulator Pb${}_{0.6}$Sn${}_{0.4}$Te
• Surface States of a System of Dirac Fermions: A Minimal Model
• Interacting Dirac fermions under spatially alternating pseudo-magnetic field: Realization of spontaneous quantum Hall effect
• Perovskite ThTaN3: a Large Thermopower Topological Crystalline Insulator
• Mirror protected Dirac fermions on a Weyl semimetal NbP surface
• Fully gapped superconductivity in In-doped topological crystalline insulator Pb${}_{0.5}$Sn${}_{0.5}$Te
• Ferroic Berry Curvature Dipole in a Topological Crystalline Insulator at Room Temperature
• Quasiparticle Interference in ZrSiS - Strongly Band-Selective Scattering Depending on Impurity Lattice Site
• Observation of Ultrahigh Mobility Surface States in a Topological Crystalline Insulator by Infrared Spectroscopy
• Defect Role in the Carrier Tunable Topological Insulator (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$ Thin Films
• Landau quantization of nearly degenerate bands, and full symmetry classification of avoided Landau-level crossings
• Topological Crystalline Magnets: Symmetry-Protected Topological Phases of Fermions
• Nanoscale Determination of the Mass Enhancement Factor in the Lightly-Doped Bulk Insulator Lead Selenide
• Metallic Surface States Probed Within the Microwave Skin Depth of the Putative Topological Insulator YBiPt Compound
• Topological nature of step edge states on the surface of topological crystalline insulator Pb${}_{0.7}$Sn${}_{0.3}$Se
• Spatially resolved Landau level spectroscopy of the topological Dirac cone of bulk-type Sb2Te3(0001): potential fluctuations and quasiparticle lifetime
• A Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator
• Non-adiabatic bulk-surface oscillations in driven topological insulators
• Pressure and Inversion Symmetry Breaking Field Driven First Order Phase Transition and Formation of Dirac Circle in Perovskites
• Mass Acquisition of Dirac Fermions in Bi4I4 by Spontaneous Symmetry Breaking
• Direct observation of a photoinduced topological phase transition in Bi-doped (Pb,Sn)Se
• Absence of a Dirac gap in ferromagnetic Cr${}_x$(Bi${}_{0.1}$Sb${}_{0.9}$)${}_{2-x}$Te${}_3$
• Surface-dependent Majorana vortex phases in topological crystalline insulators
• Large linear magnetoresistance and evidence of degeneracy lifting of valence bands in rhombohedral phase of topological crystalline insulator SnTe
• Suppression of the Spectral Weight of Topological Surface States on the Nanoscale via Local Symmetry Breaking
• Fragility of the Dirac Cone Splitting in Topological Crystalline Insulator Heterostructures
• Tip-induced Superconductivity
• Topological electronic structure of twin boundaries and twinning superlattices in the SnTe material class
• Quantum oscillations and nontrivial transport in (Bi0.92In0.08)2Se3
• Alloy theory with atomic resolution for Rashba or topological systems
• Spin Stiffness and Domain Walls in Dirac-Electron Mediated Magnets
• Electronic switching of topology in LaSbTe
• Strain-induced two-dimensional topological crystalline insulator
• Probing chiral symmetry with a topological domain wall sensor
• Reconstruction, rumpling, and Dirac states at the (001) surface of a topological crystalline insulator Pb1-xSnxSe
• Hedgehog spin texture and competing orders associated with strains on the surface of a topological crystalline insulator
• Aharonov-Bohm oscillations caused by non-topological surface states in Dirac nanowires
• One-dimensional scattering of fermions in double Dirac delta potentials
• Steerable sound transport in a 3D acoustic network
• Quantum field theory at finite temperature for 3D periodic backgrounds
• Proximity-Induced Superconductivity in a Topological Crystalline Insulator