- Open Access
Physics of the spin-orbit coupling at the surface of the model topological insulators and : Theory and experiments
Phys. Rev. B 113, 205308 – Published 8 May, 2026
DOI: https://doi.org/10.1103/mhy5-t7d1
Abstract
The dispersion of topological surface states in three-dimensional topological insulators (TIs) is commonly attributed to the atomic spin-orbit coupling (SOC) of the constituent elements. Whether the observable surface-state dispersion reflects this bare atomic value, or instead an effective SOC renormalized by surface–bulk hybridization, remains an open question. Here, we investigate this issue for the occupied and unoccupied surface-state dispersion in and by combining angle-resolved photoemission (ARPES) and time-resolved (tr-ARPES) at a fixed 1 ps delay time with ab initio one-step photoemission calculations. Comparison between experimental and calculated spectra indicates that the SOC governing the surface-state dispersion deviates from the atomic expectation, with this effect more clearly resolved in than in . The calculations, which explicitly include hybridization between topological surface states and bulk-derived surface resonance states, provide a microscopic framework for this behavior. These results indicate that the spin-orbit interaction governing topological surface states is effectively shaped by surface–bulk hybridization and can vary significantly across materials.
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References (49)
- C. L. Kane and E. J. Mele, Quantum spin Hall effect in graphene, Phys. Rev. Lett. 95, 226801 (2005).
- L. Fu, C. L. Kane, and E. J. Mele, Topological insulators in three dimensions, Phys. Rev. Lett. 98, 106803 (2007).
- J. E. Moore and L. Balents, Topological invariants of time-reversal-invariant band structures, Phys. Rev. B 75, 121306(R) (2007).
- D. Hsieh, D. Qian, L. Wray, Y. Xia, Y. S. Hor, R. J. Cava, and M. Z. Hasan, A topological Dirac insulator in a quantum spin Hall phase, Nature (London) 452, 970 (2008).
- M. Z. Hasan and C. L. Kane, Colloquium: Topological insulators, Rev. Mod. Phys. 82, 3045 (2010).
- H. Zhang, C.-X. Liu, X.-L. Qi, X. Dai, Z. Fang, and S.-C. Zhang, Topological insulators in and with a single Dirac cone on the surface, Nat. Phys. 5, 438 (2009).
- X.-L. Qi and S.-C. Zhang, Topological insulators and superconductors, Rev. Mod. Phys. 83, 1057 (2011).
- A. Bansil, H. Lin, and T. Das, Colloquium: Topological band theory, Rev. Mod. Phys. 88, 021004 (2016).
- P. Roushan, J. Seo, C. V. Parker, Y. S. Hor, D. Hsieh, D. Qian, A. Richardella, M. Z. Hasan, R. J. Cava, and A. Yazdani, Topological surface states protected from backscattering by chiral spin texture, Nature (London) 460, 1106 (2009).
- D. Pesin and A. H. MacDonald, Spintronics and pseudospintronics in graphene and topological insulators, Nat. Mater. 11, 409 (2012).
- B. Hamdou, J. Gooth, A. Dorn, E. Pippel, and K. Nielsch, Surface state dominated transport in topological insulator nanowires, Appl. Phys. Lett. 103, 193107 (2013).
- A. Pandey, R. Yadav, M. Kaur, P. Singh, A. Gupta, and S. Husale, High performing flexible optoelectronic devices using thin films of topological insulator, Sci. Rep. 11, 832 (2021).
- N. V. Leppenen and L. E. Golub, Nonlinear optical absorption and photocurrents in topological insulators, Phys. Rev. B 105, 115306 (2022).
- M. Yang, H. Zhou, and J. Wang, Topological insulators photodetectors: Preparation, advances and application challenges, Mater. Today Commun. 33, 104190 (2022).
- Y. Huang, J. D. Querales-Flores, S. W. Teitelbaum, J. Cao, T. Henighan, H. Liu, M. Jiang, G. De la Peña, V. Krapivin, J. Haber, T. Sato, M. Chollet, D. Zhu, T. Katayama, R. Power, M. Allen, C. R. Rotundu, T. P. Bailey, C. Uher, M. Trigo, et al., Ultrafast measurements of mode-specific deformation potentials of and , Phys. Rev. X 13, 041050 (2023).
- C. Cacho, A. Crepaldi, M. Battiato, J. Braun, F. Cilento, M. Zacchigna, M. Richter, O. Heckmann, E. Springate, Y. Liu, S. Dhesi, H. Berger, P. Bugnon, K. Held, M. Grioni, H. Ebert, K. Hricovini, J. Minár, and F. Parmigiani, Momentum-resolved spin dynamics of bulk and surface excited states in the topological insulator , Phys. Rev. Lett. 114, 097401 (2015).
- C. Jozwiak, J. A. Sobota, K. Gotlieb, A. F. Kemper, C. R. Rotundu, R. J. Birgeneau, Z. Hussain, D.-H. Lee, Z.-X. Shen, and A. Lanzara, Spin-polarized surface resonances accompanying topological surface state formation, Nat. Commun. 7, 13143 (2016).
- H. Hedayat, D. Bugini, H. Yi, C. Chen, X. Zhou, G. Cerullo, C. Dallera, and E. Carpene, Ultrafast evolution of bulk, surface and surface resonance states in photoexcited , Sci. Rep. 11, 4924 (2021).
- M. Bianchi, D. Guan, S. Bao, J. Mi, B. B. Iversen, P. D. King, and P. Hofmann, Coexistence of the topological state and a two-dimensional electron gas on the surface of , Nat. Commun. 1, 128 (2010).
- C. Chen, S. He, H. Weng, W. Zhang, L. Zhao, H. Liu, X. Jia, D. Mou, S. Liu, J. He, et al., Robustness of topological order and formation of quantum well states in topological insulators exposed to ambient environment, Proc. Natl. Acad. Sci. USA 109, 3694 (2012).
- K. Kuroda, M. Arita, K. Miyamoto, M. Ye, J. Jiang, A. Kimura, E. E. Krasovskii, E. V. Chulkov, H. Iwasawa, T. Okuda, K. Shimada, Y. Ueda, H. Namatame, and M. Taniguchi, Hexagonally deformed Fermi surface of the 3D topological insulator , Phys. Rev. Lett. 105, 076802 (2010).
- J. Sánchez-Barriga, M. R. Scholz, E. Golias, E. Rienks, D. Marchenko, A. Varykhalov, L. V. Yashina, and O. Rader, Anisotropic effect of warping on the lifetime broadening of topological surface states in angle-resolved photoemission from , Phys. Rev. B 90, 195413 (2014).
- M. Nomura, S. Souma, A. Takayama, T. Sato, T. Takahashi, K. Eto, K. Segawa, and Y. Ando, Relationship between Fermi surface warping and out-of-plane spin polarization in topological insulators: A view from spin- and angle-resolved photoemission, Phys. Rev. B 89, 045134 (2014).
- M. Nurmamat, E. E. Krasovskii, Y. Ishida, K. Sumida, J. Chen, T. Yoshikawa, E. V. Chulkov, K. A. Kokh, O. E. Tereshchenko, S. Shin, and A. Kimura, Ultrafast dynamics of an unoccupied surface resonance state in , Phys. Rev. B 97, 115303 (2018).
- S. Basak, H. Lin, L. A. Wray, S.-Y. Xu, L. Fu, M. Z. Hasan, and A. Bansil, Spin texture on the warped Dirac-cone surface states in topological insulators, Phys. Rev. B 84, 121401(R) (2011).
- Y. H. Wang, D. Hsieh, D. Pilon, L. Fu, D. R. Gardner, Y. S. Lee, and N. Gedik, Observation of a warped helical spin texture in from circular dichroism angle-resolved photoemission spectroscopy, Phys. Rev. Lett. 107, 207602 (2011).
- L. Fu, Hexagonal warping effects in the surface states of the topological insulator , Phys. Rev. Lett. 103, 266801 (2009).
- C.-X. Liu, X.-L. Qi, H. J. Zhang, X. Dai, Z. Fang, and S.-C. Zhang, Model Hamiltonian for topological insulators, Phys. Rev. B 82, 045122 (2010).
- E. Frantzeskakis and M. Grioni, Anisotropy effects on Rashba and topological insulator spin-polarized surface states: A unified phenomenological description, Phys. Rev. B 84, 155453 (2011).
- A. Nuber, J. Braun, F. Forster, J. Minár, F. Reinert, and H. Ebert, Surface versus bulk contributions to the Rashba splitting in surface systems, Phys. Rev. B 83, 165401 (2011).
- A. Jain, S. P. Ong, G. Hautier, W. Chen, W. D. Richards, S. Dacek, S. Cholia, D. Gunter, D. Skinner, G. Ceder, and K. A. Persson, Commentary: The materials Project: A materials genome approach to accelerating materials innovation, APL Mater. 1, 011002 (2013).
- The Materials Project, accessed: February 2024, https://next-gen.materialsproject.org/.
- K. Momma and F. Izumi, VESTA: A three-dimensional visualization system for electronic and structural analysis, J. Appl. Crystallogr. 41, 653 (2008).
- G. Malmström and J. Rundgren, A program for calculation of the reflection and transmission of electrons through a surface potential barrier, Comput. Phys. Commun. 19, 263 (1980).
- J. Braun, J. Minár, and H. Ebert, Correlation, temperature and disorder: Recent developments in the one-step description of angle-resolved photoemission, Phys. Rep. 740, 1 (2018).
- A. Bendounan, K. Aït-Mansour, J. Braun, J. Minár, S. Bornemann, R. Fasel, O. Gröning, F. Sirotti, and H. Ebert, Evolution of the Rashba spin-orbit-split Shockley state on Ag/Pt(111), Phys. Rev. B 83, 195427 (2011).
- H. Ebert et al., The Munich SPR-KKR package, version 8.6, accessed: February 2024, https://www.ebert.cup.uni-muenchen.de/index.php/en/repository/SPRKKR/lang,en-gb/.
- J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 77, 3865 (1996).
- J. Braun, K. Miyamoto, A. Kimura, T. Okuda, M. Donath, H. Ebert, and J. Minár, Exceptional behavior of -like surface resonances on W(110): The one-step model in its density matrix formulation, New J. Phys. 16, 015005 (2014).
- M. Grass, J. Braun, G. Borstel, R. Schneider, H. Durr, T. Fauster, and V. Dose, Unoccupied electronic states and surface barriers at Cu surfaces, J. Phys.: Condens. Matter 5, 599 (1993).
- C. Datzer, A. Zumbülte, J. Braun, T. Förster, A. B. Schmidt, J. Mi, B. Iversen, P. Hofmann, J. Minár, H. Ebert, P. Krüger, M. Rohlfing, and M. Donath, Unraveling the spin structure of unoccupied states in , Phys. Rev. B 95, 115401 (2017).
- S. Peli, D. Puntel, D. Kopic, B. Sockol, F. Parmigiani, and F. Cilento, Time-resolved VUV ARPES at 10.8 eV photon energy and MHz repetition rate, J. Electron Spectrosc. Relat. Phenom. 243, 146978 (2020).
- A. Crepaldi, B. Ressel, F. Cilento, M. Zacchigna, C. Grazioli, H. Berger, P. Bugnon, K. Kern, M. Grioni, and F. Parmigiani, Ultrafast photodoping and effective Fermi-Dirac distribution of the Dirac particles in , Phys. Rev. B 86, 205133 (2012).
- A. Crepaldi, F. Cilento, B. Ressel, C. Cacho, J. C. Johannsen, M. Zacchigna, H. Berger, P. Bugnon, C. Grazioli, I. C. E. Turcu, E. Springate, K. Kern, M. Grioni, and F. Parmigiani, Evidence of reduced surface electron-phonon scattering in the conduction band of by nonequilibrium ARPES, Phys. Rev. B 88, 121404(R) (2013).
- See Supplemental Material at http://link.aps.org/supplemental/10.1103/mhy5-t7d1 for the calculations at intermediate SOC values and the procedure followed to determine the binding energy of the Dirac point.
- D. Hsieh, Y. Xia, D. Qian, L. Wray, J. H. Dil, F. Meier, J. Osterwalder, L. Patthey, J. G. Checkelsky, N. P. Ong, et al., A tunable topological insulator in the spin helical Dirac transport regime, Nature (London) 460, 1101 (2009).
- I. Aguilera, C. Friedrich, and S. Blügel, Many-body corrected tight-binding Hamiltonians for an accurate quasiparticle description of topological insulators of the family, Phys. Rev. B 100, 155147 (2019).
- S. Ponzoni, F. Paßlack, M. Stupar, D. M. Janas, G. Zamborlini, and M. Cinchetti, Dirac bands in the topological insulator mapped by time-resolved momentum microscopy, Adv. Phys. Res. 2, 2200016 (2023).
- F. Boschini, D. Bugini, M. Zonno, M. Michiardi, R. P. Day, E. Razzoli, B. Zwartsenberg, M. Schneider, E. H. da Silva Neto, S. dal Conte, et al., Role of matrix elements in the time-resolved photoemission signal, New J. Phys. 22, 023031 (2020).