Positron surface state as a spectroscopic probe for characterizing surfaces of topological insulator materials
Topological insulators are attracting considerable interest due to their potential for technological applications and as platforms for exploring wide-ranging fundamental science questions. In order to exploit, fine-tune, control, and manipulate the topological surface states, spectroscopic tools whi...
| Main Authors: | , , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Published: |
American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/116632 https://orcid.org/0000-0002-2480-1211 |
| Summary: | Topological insulators are attracting considerable interest due to their potential for technological applications and as platforms for exploring wide-ranging fundamental science questions. In order to exploit, fine-tune, control, and manipulate the topological surface states, spectroscopic tools which can effectively probe their properties are of key importance. Here, we demonstrate that positrons provide a sensitive probe for topological states and that the associated annihilation spectrum provides a technique for characterizing these states. Firm experimental evidence for the existence of a positron surface state near Bi2Te2Se with a binding energy of Eb=2.7±0.2eV is presented and is confirmed by first-principles calculations. Additionally, the simulations predict a significant signal originating from annihilation with the topological surface states and show the feasibility to detect their spin texture through the use of spin-polarized positron beams. |
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