Singular robust room-temperature spin response from topological Dirac fermions

Abstract

Topological insulators are a class of solids in which the nontrivial inverted bulk band structure gives rise to metallic surface states that are robust against impurity scattering. In three-dimensional (3D) topological insulators, however, the surface Dirac fermions intermix with the conducting bulk, thereby complicating access to the low energy (Dirac point) charge transport or magnetic response. Here we use differential magnetometry to probe spin rotation in the 3D topological material family (Bi${}_2$Se${}_3$, Bi${}_2$Te${}_3$, and Sb${}_2$Te${}_3$). We report a paramagnetic singularity in the magnetic susceptibility at low magnetic fields which persists up to room temperature, and which we demonstrate to arise from the surfaces of the samples. The singularity is universal to the entire family, largely independent of the bulk carrier density, and consistent with the existence of electronic states near the spin-degenerate Dirac point of the 2D helical metal. The exceptional thermal stability of the signal points to an intrinsic surface cooling process, likely of thermoelectric origin, and establishes a sustainable platform for the singular field-tunable Dirac spin response.

20 pages, 14 figures

References in corpus (23)

• The electronic properties of graphene
• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators in Three Dimensions
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• Observation of Electron-Hole Puddles in Graphene Using a Scanning Single Electron Transistor
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• Magnetoelectric polarizability and axion electrodynamics in crystalline insulators
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
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• Spatial Fluctuations of Helical Dirac Fermions on the Surface of Topological Insulators
• Emergent quantum confinement at topological insulator surfaces
• Measurement of intrinsic Dirac fermion cooling on the surface of a topological insulator Bi${}_2$Se${}_3$ using time- and angle-resolved photoemission spectroscopy
• Surface States of Topological Insulators
• Improved Thermoelectric Cooling Based on the Thomson Effect
• Evidence of reduced surface electron-phonon scattering in the conduction band of Bi_{2}Se_{3} by non-equilibrium ARPES
• Nanoscale Spin Seebeck Rectifier: Controlling Thermal Spin Transport across Insulating Magnetic Junctions with Localized Spin
• Landau level spectroscopy of relativistic fermions with low Fermi velocity in Bi2Te3 three-dimensional topological insulator
• Spin Response of Electrons on the Surface of a Topological Insulator

Cited by in corpus (22)

• Colloquium: Topological Band Theory
• Superconductivity with topological surface state in SrxBi2Se3
• Magnetotransport properties and evidence of topological insulating state in LaSbTe
• Magnetic Proximity Effect and Interlayer Exchange Coupling of Ferromagnetic/Topological Insulator/Ferromagnetic Trilayer
• Fermi surface topology and signature of surface Dirac nodes in LaBi
• Coexistence of topological Dirac fermions in the surface and three-dimensional Dirac cone state in the bulk of ZrTe${}_5$ single crystal
• Extreme magnetoresistance induced by Zeeman effect-driven electron-hole compensation and topological protection in MoSi${}_2$
• In situ compensation method for high-precision and high-sensitivity integral magnetometry
• Prominent metallic surface conduction and the singular magnetic response of topological Dirac fermion in three-dimensional topological insulator Bi${}_{1.5}$Sb${}_{0.5}$Te${}_{1.7}$Se${}_{1.3}$
• Spin memory of the topological material under strong disorder
• Spin susceptibility of three-dimensional Dirac semimetals
• Landau theory of helical Fermi liquids
• Anomalous nuclear magnetic resonance spectra in Bi${}_2$Se${}_3$ nanowires
• Local electronic and magnetic properties of the doped topological insulators Bi${}_2$Se${}_3$:Ca and Bi${}_2$Te${}_3$:Mn investigated using ion-implanted ${}^8$Li $\beta$-NMR
• Unusual magnetoresistance oscillations in preferentially oriented p-type polycrystalline ZrTe5
• Band structure of topological insulators from noise measurements in tunnel junctions
• Non-contact mutual inductance based measurement of an inhomogeneous topological insulating state in Bi2Se3 single crystals with defects
• Emergent topological fields and relativistic phonons within the thermoelectricity in topological insulators
• Insulating Half-Heusler TmPdSb with Unusual Band Order and Metallic Surface States
• Unconventional topological phase transition from semimetal to insulator in SnBi2Te4: Role of anomalous thermal expansion
• Quasi-linear magnetoresistance and paramagnetic singularity in Hypervalent Bismuthide
• Non-hermitian off-diagonal magnetic response of Dirac fermions