1. Coherent Spin Dynamics of Electrons in CdSe Colloidal Nanoplatelets.
- Author
-
Meliakov, Sergey R., Belykh, Vasilii V., Kalitukha, Ina V., Golovatenko, Aleksandr A., Di Giacomo, Alessio, Moreels, Iwan, Rodina, Anna V., and Yakovlev, Dmitri R.
- Subjects
- *
ELECTRON spin , *NANOPARTICLES , *LARMOR precession , *FARADAY effect , *RAMAN scattering , *ELECTRON spin states , *ROTATIONAL motion , *MONOMOLECULAR films - Abstract
Coherent spin dynamics of electrons in CdSe colloidal nanoplatelets are investigated by time-resolved pump–probe Faraday rotation at room and cryogenic temperatures. We measure electron spin precession in a magnetic field and determine g-factors of 1.83 and 1.72 at low temperatures for nanoplatelets with a thickness of 3 and 4 monolayers, respectively. The dephasing time of spin precession T 2 * amounts to a few nanoseconds and has a weak dependence on temperature, while the longitudinal spin relaxation time T 1 exceeds 10 ns even at room temperature. Observations of single and double electron spin–flips confirm that the nanoplatelets are negatively charged. The spin–flip Raman scattering technique reveals g-factor anisotropy by up to 10% in nanoplatelets with thicknesses of 3, 4, and 5 monolayers. In the ensemble with a random orientation of nanoplatelets, our theoretical analysis shows that the measured Larmor precession frequency corresponds to the in-plane electron g-factor. We conclude that the experimentally observed electron spin dephasing and its acceleration in the magnetic field are not provided by the electron g-factor anisotropy and can be related to the localization of the resident electrons and fluctuations of the localization potential. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF