The spin Hall effect of Bi-Sb alloys driven by thermally excited Dirac-like electrons

Abstract

We have studied the charge to spin conversion in Bi${}_{1-x}$Sb${}_x$/CoFeB heterostructures. The spin Hall conductivity (SHC) of the sputter deposited heterostructures exhibits a high plateau at Bi-rich compositions, corresponding to the topological insulator phase, followed by a decrease of SHC for Sb-richer alloys, in agreement with the calculated intrinsic spin Hall effect of Bi${}_{1-x}$Sb${}_x$ alloy. The SHC increases with increasing thickness of the Bi${}_{1-x}$Sb${}_x$ alloy before it saturates, indicating that it is the bulk of the alloy that predominantly contributes to the generation of spin current; the topological surface states, if present in the films, play little role. Surprisingly, the SHC is found to increase with increasing temperature, following the trend of carrier density. These results suggest that the large SHC at room temperature, with a spin Hall efficiency exceeding 1 and an extremely large spin current mobility, is due to increased number of Dirac-like, thermally-excited electrons in the $L$ valley of the narrow gap Bi${}_{1-x}$Sb${}_x$ alloy.

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Cited by in corpus (39)

• Maximizing Spin-Orbit Torque Generated by the Spin Hall Effect of Pt
• Fully Spin-transparent magnetic interfaces enabled by insertion of a paramagnetic NiO layer
• Switching of Perpendicular Magnetization by Spin-Orbit Torque
• Observation of strong bulk damping-like spin-orbit torque in chemically disordered ferromagnetic single layers
• Ultrahigh efficient spin-orbit torque magnetization switching in all-sputtered topological insulator - ferromagnet multilayers
• Lack of simple correlation between switching current density and spin-orbit torque efficiency of perpendicularly magnetized spin-current generator/ferromagnet heterostructures
• Unveiling the mechanism of bulk spin-orbit torques within chemically disordered Fe${}_x$Pt${}_{1-x}$ single layers
• Energy-efficient W${}_{\text{100-x}}$Ta${}_{\text{x}}$/CoFeB/MgO spin Hall nano-oscillators
• Absence of significant spin current generation in Ti/FeCoB bilayers with strong interfacial spin-orbit coupling
• Strong Spin-Orbit Torque Induced by the Intrinsic Spin Hall Effect in Cr1-xPtx
• Efficient Spin-Orbit Torque Generation in Semiconducting WTe2 with Hopping Transport
• Spin Hall effect in a spin-1 chiral semimetal
• Light and microwave driven spin pumping across FeGaB-BiSb interface
• Boosting spin-orbit torque efficiency in spin-current generator/magnet/oxide superlattices
• Spin-orbit torques and spin Hall magnetoresistance generated by twin-free and amorphous Bi0.9Sb0.1 topological insulator films
• Spin-orbit torques and magnetotransport properties of $\alpha$-Sn and $\beta$-Sn heterostructures
• Spin Hall effect driven by the spin magnetic moment current in Dirac materials
• Highly fcc-textured Pt-Al alloy films grown on MgO(001) showing enhanced spin Hall efficiency
• Observation of gigantic spin conversion anisotropy in bismuth
• Intrinsic orbital and spin Hall effect in bismuth semimetal
• Spin Pumping into Anisotropic Dirac Electrons
• Large spin to charge conversion in topological superconductor \b{eta}-PdBi2 at room temperature
• Inplane spin orbit torque magnetization switching and its detection using the spin rectification effect at sub-GHz frequencies
• Magneto-transport and Berry phase in magnetically doped Bi${}_{0.97-x}$Sb${}_{0.03}$ single crystals
• Disorder- and Topology-Enhanced Fully Spin-Polarized Currents in Nodal Chain Spin-Gapless Semimetals
• Anisotropic spin Hall and spin Nernst effects in bismuth semimetal
• Estimation of spin-orbit torques in the presence of current-induced magnon creation and annihilation
• Local Observations of Orbital Diamagnetism and Excitation in Three-Dimensional Dirac Fermion Systems Bi${}_{1-x}$Sb${}_x$
• Impact of inherent energy barrier on spin-orbit torques in magnetic-metal/semimetal heterojunctions
• Interface enhanced helicity dependent photocurrent in metal/semimetal bilayers
• Spin Hall conductivity in Bi${}_{1-x}$Sb${}_x$ as an experimental test of bulk-boundary correspondence
• Preparation and Characterization of High Quality Bi1-xSbx Thin Films: A Sputtering Deposition Approach
• A Two-Field-Scan Harmonic Hall Voltage Analysis For Fast, Accurate Quantification Of Spin-Orbit Torques In Magnetic Heterostructures
• Negligible current-induced torque from the bulk and interface of Al
• Temperature dependence of charge-to-spin conversion in rhombohedral (110) bismuth thin film
• Emergence of giant spin-orbit torque in a two-dimensional hole gas on the hydrogen-terminated diamond surface
• Gate-tunable charge-spin interconversion in graphene/heavy-metal heterostructures
• Current induced magneto-optical Kerr effect as a probe of Dirac carriers in Bi${}_{1-x}$Sb${}_x$ alloy
• Charge-to-spin conversion in epitaxial and polycrystalline Bi and Bi/Ag layers