Momentum resolved spin dynamics of bulk and surface excited states in the topological insulator $\mathrm{B}{\mathrm{i}}_2\mathrm{S}{\mathrm{e}}_3$

Abstract

The prospective of optically inducing a spin polarized current for spintronic devices has generated a vast interest in the out-of-equilibrium electronic and spin structure of topological insulators (TIs). In this Letter we prove that only by measuring the spin intensity signal over several order of magnitude in spin, time and angle resolved photoemission spectroscopy (STAR-PES) experiments is it possible to comprehensively describe the optically excited electronic states in TIs materials. The experiments performed on $\mathrm{B}{\mathrm{i}}_2\mathrm{S}{\mathrm{e}}_3$ reveal the existence of a Surface-Resonance-State in the 2nd bulk band gap interpreted on the basis of fully relativistic ab-initio spin resolved photoemission calculations. Remarkably, the spin dependent relaxation of the hot carriers is well reproduced by a spin dynamics model considering two non-interacting electronic systems, derived from the excited surface and bulk states, with different electronic temperatures.

5 pages and 4 figures

References in corpus (6)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• 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
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• Ultrafast surface carrier dynamics in the topological insulator Bi2Te3
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Cited by in corpus (19)

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• Sub-picosecond spin dynamics of excited states in the topological insulator Bi${}_2$Te${}_3$
• Weak Localization and Antilocalization in Topological Materials with Impurity Spin-Orbit Interactions
• Advancing time- and angle-resolved photoemission spectroscopy: The role of ultrafast laser development
• Electron spin dynamics of two-dimensional layered materials
• Time-, spin-, and angle-resolved photoemission spectroscopy with a 1-MHz 10.7-eV pulse laser
• Ultrafast Momentum-resolved Hot Electron Dynamics in the Two-dimensional Topological Insulator Bismuthene
• Ultrafast Hidden Spin Polarization Dynamics of Bright and Dark Excitons in 2H-WSe${}_2$
• Selective Trapping of Hexagonally Warped Topological Surface States in a Triangular Quantum Corral
• Coulomb drag in topological materials
• Control of intervalley scattering in Bi${}_2$Te${}_3$ via temperature-dependent band renormalization
• Topological spin textures in electronic non-Hermitian systems
• Nonequilibrium topological spin textures in momentum space
• One step model of photo-emission at finite temperatures: spin fluctuations of Fe(001)
• Surface spectroscopy and surface-bulk hybridization of Weyl semimetals
• Floquet spin textures in optically pumped non-Hermitian surface states