Selective probing of photo-induced charge and spin dynamics in the bulk and surface of a topological insulator

Abstract

Topological insulators possess completely different spin-orbit coupled bulk and surface electronic spectra that are each predicted to exhibit exotic responses to light. Here we report time-resolved fundamental and second harmonic optical pump-probe measurements on the topological insulator Bi2Se3 to independently measure its photo-induced charge and spin dynamics with bulk and surface selectivity. Our results show that a transient net spin density can be optically induced in both the bulk and surface, which may drive spin transport in topological insulators. By utilizing a novel rotational anisotropy analysis we are able to separately resolve the spin de-polarization, intraband cooling and interband recombination processes following photo-excitation, which reveal that spin and charge degrees of freedom relax on very different time scales owing to strong spin-orbit coupling.

Accepted to Phys. Rev. Lett

References in corpus (13)

• 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 Field Theory of Time-Reversal Invariant Insulators
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Topological origin of subgap conductance in insulating bilayer graphene
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Bulk Fermi surface coexistence with Dirac surface state in Bi${}_2$Se${}_3$: a comparison of photoemission and Shubnikov-de Haas measurements
• Strong surface scattering in ultrahigh mobility Bi2Se3 topological insulator crystals
• Photoinduced transition between conventional and topological insulators in two-dimensional electronic systems
• Surface State Transport and Ambipolar Electric Field Effect in Bi2Se3 Nanodevices
• Nonlinear optical probe of tunable surface electrons on a topological insulator
• Ultrafast carrier and phonon dynamics in Bi2Se3 crystals

Cited by in corpus (72)

• Topological Insulator Materials
• Direct visualization of current induced spin accumulation in topological insulators
• Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3
• Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure
• Measurement of intrinsic Dirac fermion cooling on the surface of a topological insulator Bi${}_2$Se${}_3$ using time- and angle-resolved photoemission spectroscopy
• Ultrafast surface carrier dynamics in the topological insulator Bi2Te3
• Ultrafast helicity control of surface currents in topological insulators with near-unity fidelity
• Direct Optical Coupling to an Unoccupied Dirac Surface State in the Topological Insulator Bi${}_2$Se${}_3$
• Topological Floquet Spectrum in Three Dimensions via a Two-Photon Resonance
• Time- and Angle-Resolved Photoemission Studies of Quantum Materials
• Ultrafast carrier dynamics in thin-films of the topological insulator Bi2Se3
• Direct measurement of proximity-induced magnetism at the interface between a topological insulator and a ferromagnet
• Enhancement of bulk photovoltaic effect in topological insulators
• Ultrafast photodoping and effective Fermi-Dirac distribution of the Dirac particles in Bi2Se3
• Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation
• Helicity dependent photocurrent in electrically gated (Bi,Sb)_2Te_3 thin films
• Ultrafast Electron Dynamics in the Topological Insulator Bi2Se3 Studied by Time-Resolved Photoemission Spectroscopy
• Time-resolved terahertz dynamics in thin films of the topological insulator Bi${}_2$Se${}_3$
• Unraveling photoinduced spin dynamics in topological insulator Bi2Se3
• Generation of Transient Photocurrents in the Topological Surface State of Sb${}_2$Te${}_3$ by Direct Optical Excitation with Mid-Infrared Pulses
• Ultrafast spin polarization control of Dirac fermions in topological insulators
• Milliwatt terahertz harmonic generation from topological insulator metamaterials
• Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators
• Effect of carrier recombination on ultrafast carrier dynamics in thin films of the topological insulator Bi2Se3
• Terahertz signatures of ultrafast Dirac fermion relaxation at the surface of topological insulators at room temperature
• Magnetization signatures of light-induced quantum Hall edge states
• Sub-picosecond spin dynamics of excited states in the topological insulator Bi${}_2$Te${}_3$
• Infrared/Terahertz Spectra of the Photogalvanic Effect in (Bi,Sb)Te based Three Dimensional Topological Insulators
• Ultrafast Energy- and Momentum-resolved Surface Dirac Photocurrents in the Topological Insulator Sb${}_2$Te${}_3$
• Clarifying ultrafast carrier dynamics in ultrathin films of the topological insulator Bi2Se3 using transient absorption spectroscopy
• Nonlinear Optical Observation of Coherent Acoustic Dirac Plasmons in Thin-Film Topological Insulators
• Acoustic phonon dynamics in thin-films of the topological insulator Bi2Se3
• Resonance-type thickness dependence of optical second harmonic generation in thin-films of the topological insulator Bi2Se3
• Coherent control of optical injection of spin and currents in topological insulators
• Revealing Optical Transitions and Carrier Recombination Dynamics within the Bulk Band Structure of Bi2Se3
• Helicity dependent photovoltaic effect in Bi2Se3 under normal incident light
• Electromagnetic spin polarization on the surface of topological insulator
• Spin-momentum locked interaction between guided photons and surface electrons in topological insulators
• Local photocurrent generation in thin films of the topological insulator Bi2Se3
• Reading charge transport from spin dynamics on the surface of topological insulator
• An antiferromagnetic diode effect in even-layered MnBi2Te4
• Electrostatic effects and band-bending in doped topological insulators
• Coherent ultrafast spin-dynamics probed in three dimensional topological insulators
• Cavity Induced Topology in Graphene
• Band bending at the surface of Bi${}_2$Se${}_3$ studied from first principles
• Time-, spin-, and angle-resolved photoemission spectroscopy with a 1-MHz 10.7-eV pulse laser
• Impact of ultrafast transport on the high-energy states of a photoexcited topological insulator
• Observation of terahertz second harmonic generation from Dirac surface states in the topological insulator Bi${}_2$Se${}_3$
• Imaging topologically protected transport with quantum degenerate gases
• Optical bulk-boundary dichotomy in a quantum spin Hall insulator
• A cascading nonlinear magneto-optical effect in topological insulators
• Ultrafast Evolution of Bulk, Surface and Surface Resonance States in Photoexcited Bi${}_2$Te${}_3$
• Coherent surface-to-bulk vibrational coupling in the 2D topologically trivial insulator Bi2Se3 monitored by ultrafast transient absorption spectroscopy
• Non-adiabatic bulk-surface oscillations in driven topological insulators
• Pump-triple sum-frequency-probe spectroscopy of transition metal dichalcogenides
• Current amplification and relaxation in Dirac systems
• Ultrafast opto-magnetic effects induced by nitrogen-vacancy centers in diamond crystals
• Comment on 'Unraveling Photoinduced Spin Dynamics in the Topological Insulator Bi2Se3'
• Extremely low-energy collective modes in a quasi-one-dimensional system
• Instantaneous Photon Drag Currents in Topological Insulators
• A compact and stable incidence-plane-rotating second harmonics detector
• Two-photon IR pumped UV-Vis transient absorption spectroscopy of Dirac fermions in the 2D and 3D topological insulator Bi2Se3
• Ultrafast switching of topological invariants by light-driven strain
• Topological Insulator Metamaterial with Giant Circular Photogalvanic Effect
• Photon Energy Dependence of Kerr Rotation in Chalcogenide Superlattices
• Nonequilibrium carrier and phonon dynamics in the ferrimagnetic semiconductor Mn${}_3$Si${}_2$Te${}_6$
• Unoccupied Topological Surface State in MnBi${}_2$Te${}_4$
• Observation of spin Nernst photocurrents in topological insulators
• Ultrafast electron dynamics at the Dirac node of the topological insulator Sb${}_2$Te${}_3$
• Band structure of Bi surfaces formed on Bi2Se3 upon exposure to air
• Research on topological materials using ultrafast spectroscopy
• Exotic superfluid of trapped Fermi gases with spin-orbit coupling in dimensional crossover