Geometric decoherence of valley excitons in monolayer transition metal dichachogenides
| Autor: | Hongchen Fu, Zhirui Gong, Bin Wang, Zhanfeng Jiang, Fuming Xu |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Quantum decoherence Photon Condensed matter physics Exciton 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics Polarization (waves) Photochemistry 01 natural sciences Dipole symbols.namesake 0103 physical sciences Faraday effect Valleytronics Monolayer symbols General Materials Science 010306 general physics 0210 nano-technology Physics::Atmospheric and Oceanic Physics |
| Zdroj: | Journal of physics. Condensed matter : an Institute of Physics journal. 29(29) |
| ISSN: | 1361-648X |
| Popis: | We study the effects of the Berry phases of the valley excitons in the monolayer transition metal dichalcogenides (TMDs) when the valley excitons are manipulated by an external terahertz field. We find that the decoherence of the valley degree of freedom of the valley excitons is spontaneously induced because of the different Berry phases of valley excitons accumulated along the opposite trajectories under the manipulation of the external field. It is called the geometric decoherence because it completely results from the geometric phases. The obvious phenomenon related to such spontaneous decoherence is the gradual decrement of the dipole moment matrix element of the valley exciton and consequently the decrement of the emitted signals after the valley excitons are recombined. Moreover, another effect due to the Berry phases is the giant Faraday rotation of the polarization of the emitted photons. Such imperfection of the valley degree of freedom is supposed to provide the potential limits of the valleytronics based on the TMDs optoelecronic devices. |
| Databáze: | OpenAIRE |
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