arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2403.01029cond-mat.mes-hallcond-mat.mtrl-sci
收藏

揭示模型拓扑绝缘体表面自旋-轨道耦合的物理机制:从理论到实验

Unveiling the physics of the spin-orbit coupling at the surface of a model topological insulator: from theory to experiments

Denny Puntel, Simone Peli, Wibke Bronsch, Federico Cilento, Hubert Ebert, Jürgen Braun, Fulvio Parmigiani

AI总结:

本文提出以泵浦-探测ARPES数据校准的ab initio模型,揭示拓扑绝缘体表面共振态杂化导致70%–85%的原子自旋-轨道耦合转移至表面态,并由六方翘曲验证。

摘要:

自旋-轨道相互作用会影响拓扑绝缘体的能带结构,其作用不仅限于在体带中打开反转带隙;理解其对表面态的影响,对于把握这些奇异态背后的物理机制至关重要。本文提出一种以泵浦-探测角分辨光电子能谱数据为基准的 ab initio(从头算)方法,用于模拟自旋-轨道耦合对拓扑绝缘体表面态的影响。该方法的关键创新在于,能够考虑自旋-轨道耦合通过与表面共振态杂化而部分转移至表面态的过程。在拓扑绝缘体中,转移的自旋-轨道耦合比例会影响表面态六方翘曲的强度,我们将其作为检验模型复现实验色散能力的判据。对未占据以及部分占据的狄拉克锥进行计算与测量的比较表明,通过与共振态杂化转移到表面态的自旋-轨道耦合比例,介于其完整原子值的70%至85%之间。这为改进拓扑绝缘体表面态性质的建模提供了宝贵见解,可服务于科学研究和技术应用。

英文摘要:

Spin-orbit interaction affects the band structure of topological insulators beyond the opening of an inverted gap in the bulk bands, and the understanding of its effects on the surface states is of primary importance to access the underlying physics of these exotic states. Here, we propose an $\textit{ab initio}$ approach benchmarked by pump-probe angle-resolved photoelectron spectroscopy data to model the effect of spin-orbit coupling on the surface states of a topological insulator. The critical novelty of our approach lies in the possibility of accounting for a partial transfer of the spin-orbit coupling to the surface states, mediated by the hybridization with the surface resonance states. In topological insulators, the fraction of transferred spin-orbit coupling influences the strength of the hexagonal warping of the surface states, which we use as a telltale of the capability of our model to reproduce the experimental dispersion. The comparison between calculations and measurements, of both the unoccupied and part of the occupied Dirac cone, indicates that the fraction of spin-orbit coupling transferred to the surface states by hybridization with the resonance states is between 70% and 85% of its full atomic value. This offers a valuable insight to improve the modeling of surface state properties in topological insulators for both scientific purposes and technological applications.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑