Robust behavior and spin-texture stability of the topological surface state in Bi2Se3 upon deposition of gold
- The Dirac point of a topological surface state (TSS) is protected against gapping by time-reversal symmetry. Conventional wisdom stipulates, therefore, that only through magnetisation may a TSS become gapped. However, non-magnetic gaps have now been demonstrated in Bi2Se3 systems doped with Mn or In, explained by hybridisation of the Dirac cone with induced impurity resonances. Recent photoemission experiments suggest that an analogous mechanism applies even when Bi2Se3 is surface dosed with Au. Here, we perform a systematic spin- and angle-resolved photoemission study of Au-dosed Bi2Se3. Although there are experimental conditions wherein the TSS appears gapped due to unfavourable photoemission matrix elements, our photon-energy-dependent spectra unambiguously demonstrate the robustness of the Dirac cone against high Au coverage. We further show how the spin textures of the TSS and its accompanying surface resonances remain qualitatively unchanged following Au deposition, and discuss the mechanism underlying the suppression of theThe Dirac point of a topological surface state (TSS) is protected against gapping by time-reversal symmetry. Conventional wisdom stipulates, therefore, that only through magnetisation may a TSS become gapped. However, non-magnetic gaps have now been demonstrated in Bi2Se3 systems doped with Mn or In, explained by hybridisation of the Dirac cone with induced impurity resonances. Recent photoemission experiments suggest that an analogous mechanism applies even when Bi2Se3 is surface dosed with Au. Here, we perform a systematic spin- and angle-resolved photoemission study of Au-dosed Bi2Se3. Although there are experimental conditions wherein the TSS appears gapped due to unfavourable photoemission matrix elements, our photon-energy-dependent spectra unambiguously demonstrate the robustness of the Dirac cone against high Au coverage. We further show how the spin textures of the TSS and its accompanying surface resonances remain qualitatively unchanged following Au deposition, and discuss the mechanism underlying the suppression of the spectral weight.…
| Author details: | Oliver J. ClarkORCiD, Friedrich FreyseORCiD, L. V. Yashina, Oliver RaderORCiDGND, Jaime Sanchez-BarrigaORCiDGND |
|---|---|
| DOI: | https://doi.org/10.1038/s41535-022-00443-9 |
| ISSN: | 2397-4648 |
| Title of parent work (English): | npj quantum materials |
| Publisher: | Nature Publishing Group |
| Place of publishing: | London |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2022/03/28 |
| Publication year: | 2022 |
| Release date: | 2024/01/03 |
| Tag: | Electronic properties and materials; Topological matter |
| Volume: | 7 |
| Issue: | 1 |
| Article number: | 36 |
| Number of pages: | 7 |
| Funding institution: | Impuls- und Vernetzungsfonds der Helmholtz-Gemeinschaft [HRSF-0067] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
| Peer review: | Referiert |
| Publishing method: | Open Access / Gold Open-Access |
| DOAJ gelistet | |
| License (German): |  CC-BY - Namensnennung 4.0 International |
