Optical bistability and self-opacity in magnetically doped monolayer transition metal dichalcogenides
| Autor: | Malcolm Regan, Ki Wook Kim, Yuriy G. Semenov |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Magnetic moment Condensed matter physics Spins 02 engineering and technology Magnetic semiconductor 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences Optical bistability symbols.namesake Stark effect 0103 physical sciences symbols 010306 general physics 0210 nano-technology Electronic band structure Excitation |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.214426 |
| Popis: | Magneto-optical control of optical absorption spectra is theoretically investigated in two-dimensional (2D) dilute magnetic semiconductors such as monolayer transition metal dichalcogenides (TMDs) doped with magnetic ions. The underlying mechanism relies on efficient spin transfer between spin-polarized photoexcited carriers and localized magnetic ions via exchange scattering, and subsequent shifts in the electronic band structure induced by the resulting time-reversal symmetry breaking. A self-consistent model based on a rate equation is developed to analyze dynamical polarization of itinerant carrier spins and localized magnetic moments under circularly polarized optical excitation and the corresponding band modifications. The results illustrate that nonlinear effects such as optical bistability and self-opacity can indeed be achieved efficiently for a range of excitation power and frequency. In particular, the addition of magnetic dopants is shown to reduce the optical power required for the necessary band shifts by four orders of magnitude compared to that via the optical Stark effect in a nonmagnetic counterpart. Further investigation in a multidimensional parameter space elucidates the conditions for practical realization of the desired nonlinear effects in 2D TMD monolayers. |
| Databáze: | OpenAIRE |
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