Spin texture tunability in Mn${}_{1-x}$Ge${}_x$Bi${}_2$Te${}_4$ through varying Ge Concentration

Abstract

The spin-resolved dispersion dependencies for the topological insulator Mn${}_{1-x}$Ge${}_x$Bi${}_2$Te${}_4$ in the $\bar{\mathrm{K}}\bar{\Gamma }{\bar{\mathrm{K}}}^{\prime }$ path of the Brillouin zone were studied by spin- and angle-resolved photoemission spectroscopy using laser radiation (Laser Spin-ARPES) with variation of the concentration of substitutional Ge atoms (x from 0.1 to 0.8) for in-plane ($s_x$) and out-of-plane ($s_z$) spin orientation. The formation of Rashba-like states is shown, which shift to lower energies with increasing Ge concentration. In the region of Ge concentrations from 50% to 75%, the contribution of these states to the formed spin-dependent dispersions becomes predominant. A pronounced in-plane ($s_y$) spin polarization, asymmetric for opposite $\pm k_{\parallel }$ directions, is revealed for the Dirac cone states, while the Rashba-like states exhibit a pronounced asymmetry in both in-plane ($s_y$) and out-of-plane ($s_z$) spin polarizations. Theoretical calculations confirmed the asymmetric polarization of the Rashba-like states formed in the $\bar{\mathrm{K}}\bar{\Gamma }{\bar{\mathrm{K}}}^{\prime }$ path of the BZ, simultaneously for in-plane and out-of-plane spin orientation. Constant energy maps for Rashba-like states show a pronounced $s_z$ spin component along the $\bar{\Gamma }\bar{\mathrm{K}}$ direction, with a sign change as the contour crosses the $\bar{\Gamma }\bar{\mathrm{M}}$ direction. The observed spin polarization can influence the development of spin devices based on magnetic topological insulators.

References in corpus (34)

• Topological insulators and superconductors
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Topological Field Theory of Time-Reversal Invariant Insulators
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Spin Transfer Torque Generated by the Topological Insulator Bi_2Se_3
• Prediction and observation of the first antiferromagnetic topological insulator
• Intrinsic magnetic topological insulators in van der Waals layered MnBi${}_2$Te${}_4$-family materials
• Topological axion states in magnetic insulator MnBi${}_2$Te${}_4$ with the quantized magnetoelectric effect
• Giant Spin-splitting in the Bi/Ag(111) Surface Alloy
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Experimental realization of an intrinsic magnetic topological insulator
• Colloquium: Quantum anomalous Hall effect
• Gapless surface Dirac cone in antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Topological Electronic Structure and Its Temperature Evolution in Antiferromagnetic Topological Insulator MnBi2Te4
• Emergent quantum confinement at topological insulator surfaces
• Orbital-Angular-Momentum Based Origin of Rashba-Type Surface Band Splitting
• Observation of a warped helical spin-texture in Bi${}_2$Se${}_3$ from circular dichroism angle-resolved photoemission spectroscopy
• Photoelectron spin-flipping and texture manipulation in a topological insulator
• Gapless Dirac surface states in the antiferromagnetic topological insulator MnBi2Te4
• Surface orbitronics: new twists from orbital Rashba physics
• Two-Dimensional Materials for Energy-Efficient Spin-Orbit Torque Devices
• Orbital-Selective Spin Texture and its Manipulation in a Topological Insulator
• Intrinsic magnetic topological insulators
• Topological phase transition in layered magnetic compound MnSb2Te4: Spin-orbit coupling and interlayer coupling dependeces
• Sample-dependent Dirac point gap in MnBi${}_2$Te${}_4$ and its response to the applied surface charge: a combined photoemission and ab initio study
• Novel Spin-texture on the warped Dirac-cone surface states in topological insulators
• Prediction of Weyl semimetal, AFM topological insulator, nodal line semimetal, and Chern insulator phases in Bi2MnSe4
• Magnetic dilution effect and topological phase transitions in (Mn${}_{1-x}$Pb${}_x$)Bi${}_2$Te${}_4$
• The elusive quantum anomalous Hall effect in MnBi2Te4: a materials perspective
• Effect on the Electronic and Magnetic Properties of Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$ with Sn Doping
• Laser-based angle-resolved photoemission spectroscopy with micrometer spatial resolution and detection of three-dimensional spin vector
• Magnetic warping in topological insulators
• Momentum-inversion symmetry breaking on the Fermi surface of magnetic topological insulators
• Interfacing Quantum Spin Hall and Quantum Anomalous Hall insulators: Bi bilayer on MnBi${}_2$Te${}_4$-family materials