Observation of Floquet-Bloch States on the Surface of a Topological Insulator
The unique electronic properties of the surface electrons in a topological insulator are protected by time-reversal symmetry. Circularly polarized light naturally breaks time-reversal symmetry, which may lead to an exotic surface quantum Hall state. Using time- and angle-resolved photoemission spect...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | en_US |
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2014
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| Online Access: | http://hdl.handle.net/1721.1/88434 https://orcid.org/0000-0002-6394-4987 https://orcid.org/0000-0001-8217-8213 |
| _version_ | 1811088624073048064 |
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| author | Wang, Y. H. Steinberg, Hadar Jarillo-Herrero, Pablo Gedik, Nuh |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Wang, Y. H. Steinberg, Hadar Jarillo-Herrero, Pablo Gedik, Nuh |
| author_sort | Wang, Y. H. |
| collection | MIT |
| description | The unique electronic properties of the surface electrons in a topological insulator are protected by time-reversal symmetry. Circularly polarized light naturally breaks time-reversal symmetry, which may lead to an exotic surface quantum Hall state. Using time- and angle-resolved photoemission spectroscopy, we show that an intense ultrashort midinfrared pulse with energy below the bulk band gap hybridizes with the surface Dirac fermions of a topological insulator to form Floquet-Bloch bands. These photon-dressed surface bands exhibit polarization-dependent band gaps at avoided crossings. Circularly polarized photons induce an additional gap at the Dirac point, which is a signature of broken time-reversal symmetry on the surface. These observations establish the Floquet-Bloch bands in solids and pave the way for optical manipulation of topological quantum states of matter. |
| first_indexed | 2024-09-23T14:04:56Z |
| format | Article |
| id | mit-1721.1/88434 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T14:04:56Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | mit-1721.1/884342022-09-28T18:16:21Z Observation of Floquet-Bloch States on the Surface of a Topological Insulator Wang, Y. H. Steinberg, Hadar Jarillo-Herrero, Pablo Gedik, Nuh Massachusetts Institute of Technology. Department of Physics Wang, Y. H. Steinberg, Hadar Jarillo-Herrero, Pablo Gedik, Nuh The unique electronic properties of the surface electrons in a topological insulator are protected by time-reversal symmetry. Circularly polarized light naturally breaks time-reversal symmetry, which may lead to an exotic surface quantum Hall state. Using time- and angle-resolved photoemission spectroscopy, we show that an intense ultrashort midinfrared pulse with energy below the bulk band gap hybridizes with the surface Dirac fermions of a topological insulator to form Floquet-Bloch bands. These photon-dressed surface bands exhibit polarization-dependent band gaps at avoided crossings. Circularly polarized photons induce an additional gap at the Dirac point, which is a signature of broken time-reversal symmetry on the surface. These observations establish the Floquet-Bloch bands in solids and pave the way for optical manipulation of topological quantum states of matter. United States. Dept. of Energy (Award DE-FG02-08ER46521) United States. Dept. of Energy (Award DE-SC0006423) United States. Army Research Office (Grant W911NF-09-1-0170) United States. Dept. of Energy. Division of Materials Sciences and Engineering (Award DE-SC0006418) 2014-07-18T14:10:27Z 2014-07-18T14:10:27Z 2013-10 Article http://purl.org/eprint/type/JournalArticle 0036-8075 1095-9203 http://hdl.handle.net/1721.1/88434 Wang, Y. H., H. Steinberg, P. Jarillo-Herrero, and N. Gedik. “Observation of Floquet-Bloch States on the Surface of a Topological Insulator.” Science 342, no. 6157 (October 25, 2013): 453–457. https://orcid.org/0000-0002-6394-4987 https://orcid.org/0000-0001-8217-8213 en_US http://dx.doi.org/10.1126/science.1239834 Science Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf arXiv |
| spellingShingle | Wang, Y. H. Steinberg, Hadar Jarillo-Herrero, Pablo Gedik, Nuh Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title | Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title_full | Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title_fullStr | Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title_full_unstemmed | Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title_short | Observation of Floquet-Bloch States on the Surface of a Topological Insulator |
| title_sort | observation of floquet bloch states on the surface of a topological insulator |
| url | http://hdl.handle.net/1721.1/88434 https://orcid.org/0000-0002-6394-4987 https://orcid.org/0000-0001-8217-8213 |
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