| Autor: |
Khatri, Prince, Ramsay, Andrew J., Malein, Ralph Nicholas Edward, Chong, Harold M. H., Luxmoore, Isaac J. |
| Zdroj: |
Nano Letters; June 2020, Vol. 20 Issue: 6 p4256-4263, 8p |
| Abstrakt: |
We report on multicolor excitation experiments with color centers in hexagonal boron nitride at cryogenic temperatures. We demonstrate controllable optical switching between bright and dark states of color centers emitting around 2 eV. Resonant, or quasi-resonant, excitation of photoluminescence also pumps the color center, via a two-photon process, into a dark state, where it becomes trapped. Repumping back into the bright state has a step-like spectrum with a defect-dependent threshold between 2.25 and 2.6 eV. This behavior is consistent with photoionization and charging between optically bright and dark states of the defect. Furthermore, a second zero phonon line, detuned by +0.4 eV, is observed in absorption with orthogonal polarization to the emission, evidencing an additional energy level in the color center. |
| Databáze: |
Supplemental Index |
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