Nanocrystal shape and the mechanism of exciton spin relaxation.
The rate of exciton spin relaxation (flips) between the bright exciton states (F = +/-1) of CdSe nanocrystals is reported as a function of shape, for dots and nanorods. The spin relaxation is measured using an ultrafast transient grating method with a crossed linearly polarization sequence. It is found that the spin relaxation rate depends on the radius, not length, of the nanocrystals. That observation is explained by deriving an expression for the electronic coupling matrix element that mixes the bright exciton states.
Scholes
Gregory D
GD
Department of Chemistry, 80 St. George Street, Institute for Optical Sciences, and Centre for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 Canada. gscholes@chem.utoronto.ca
Kim
Jeongho
J
Wong
Cathy Y
CY
Huxter
Vanessa M
VM
Nair
P Sreekumari
PS
Fritz
Karolina P
KP
Kumar
Sandeep
S
D019187:Cadmium Compounds / Q000737:chemistry* / Q000528:radiation effects; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D008027:Light; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects; D045663:Quantum Dots; D013113:Spin Labels; D013440:Sulfides / Q000737:chemistry* / Q000528:radiation effects
D019187:Cadmium Compounds; D013113:Spin Labels; D013440:Sulfides; C034939:cadmium sulfide