Direct comparison of current-induced spin polarization in topological insulator Bi2Se3 and InAs Rashba states

Abstract

Three-dimensional topological insulators (TIs) exhibit time-reversal symmetry protected, linearly dispersing Dirac surface states. Band bending at the TI surface may also lead to coexisting trivial two-dimensional electron gas (2DEG) states with parabolic energy dispersion that exist as spin-split pairs due to Rashba spin-orbit coupling (SOC). A bias current is expected to generate spin polarization in both systems arising from their helical spin-momentum locking. However, their induced spin polarization is expected to be different in both magnitude and sign. Here, we compare spin potentiometric measurements of bias current-generated spin polarization in Bi2Se3(111) films where Dirac surface states coexist with trivial 2DEG states, with identical measurements on InAs(001) samples where only trivial 2DEG states are present. We observe spin polarization arising from spin-momentum locking in both cases, with opposite signs of the spin voltage. We present a model based on spin dependent electrochemical potentials to directly derive the signs expected for the TI surface states, and unambiguously show that the dominant contribution to the current-generated spin polarization measured in the TI is from the Dirac surface states. This direct electrical access of the helical spin texture of Dirac and Rashba 2DEG states is an enabling step towards the electrical manipulation of spins in next generation TI and SOC based quantum devices.

References in corpus (24)

• Topological Insulators
• Topological Insulators in Three Dimensions
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• New Perspectives for Rashba Spin-Orbit Coupling
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Spintronics and Pseudospintronics in Graphene and Topological Insulators
• Spin Polarization and Transport of Surface States in the Topological Insulators Bi2Se3 and Bi2Te3 from First Principles
• Large tuneable Rashba spin splitting of a two-dimensional electron gas in Bi2Se3
• Spatial Fluctuations of Helical Dirac Fermions on the Surface of Topological Insulators
• Emergent quantum confinement at topological insulator surfaces
• Electric-field control of spin-orbit torque in a magnetically doped topological insulator
• Spin and Charge Transport on the Surface of a Topological Insulator
• Van der Waals epitaxy of Bi2Se3 on Si(111) vicinal surface: An approach to prepare high-quality thin films of topological insulator
• Two-dimensional surface charge transport in topological insulators
• Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi_1.5 Sb_0.5 Te_1.7 Se_1.3
• Room Temperature Electrical Detection of Spin Polarized Currents in Topological Insulators
• Electrical injection and detection of spin-polarized currents in topological insulator Bi2Te2Se
• Surface Scattering via Bulk Continuum States in the 3D Topological Insulator Bi${}_2$Se${}_3$
• Mapping the chemical potential dependence of current-induced spin polarization in a topological insulator
• Tunneling Planar Hall Effect in Topological Insulators: Spin-Valves and Amplifiers
• Magnetic control of spin-orbit fields: a first-principles study of Fe/GaAs junctions
• Surface-to-bulk scattering in topological insulator films
• Spin Nomenclature for Semiconductors and Magnetic Metals
• Effects of surface-bulk hybridization in 3D topological `metals'

Cited by in corpus (19)

• Origin and evolution of surface spin current in topological insulators
• Strong influence of spin-orbit coupling on magnetotransport in two-dimensional hole systems
• Spin transport in ferromagnet-InSb nanowire quantum devices
• Electrical detection of surface spin polarization of candidate topological Kondo insulator SmB6
• Band tilt induced nonlinear Nernst effect in topological insulators: An efficient generation of high-performance spin polarization
• Topological insulator spin transistor
• Non-linear antidamping spin-orbit torque originating from intra-band transport on the warped surface of a topological insulator
• Coherent surface-to-bulk vibrational coupling in the 2D topologically trivial insulator Bi2Se3 monitored by ultrafast transient absorption spectroscopy
• Room temperature nonlocal detection of charge-spin interconversion in a topological insulator
• Resonant Tunneling Anisotropic Magnetoresistance Induced by Magnetic Proximity
• Detection of current induced spin polarization in epitaxial Bi${}_2$Te${}_3$ thin film
• A topological current divider
• Kondo enhancement of current induced spin accumulation in a quantum dot
• Interplay between Topological States and Rashba States as Manifested on Surface Steps at Room Temperature
• Spintronic Quantum Phase Transition in a $Graphene/P{b}_{0.24}S{n}_{0.76}Te$ Heterostructure with Giant Rashba Spin-Orbit Coupling
• Correspondence: Reply to "On the understanding of current-induced spin polarization of 3D topological insulators"
• Spin-helical detection in a semiconductor quantum device with ferromagnetic contacts
• Promoted current-induced spin polarization in inversion symmetry broken topological insulator thin films
• Heavy-hole band splitting observed in mobility spectrum of p-type InAs grown on GaAs substrate