State Selective Pumping Reveals Spin-Relaxation Pathways in CdSe Quantum Dots
Langue
en
Article de revue
Ce document a été publié dans
Nano Letters. 2014-07-21, vol. 14, n° 8, p. 4480-4485
American Chemical Society
Résumé en anglais
The band-edge exciton in elongated CdSe nanocrystals is composed of an upper and lower manifold associated with heavy and light holes in which the energy separation is sensitive to the nanocrystal shape. Using resonant ...Lire la suite >
The band-edge exciton in elongated CdSe nanocrystals is composed of an upper and lower manifold associated with heavy and light holes in which the energy separation is sensitive to the nanocrystal shape. Using resonant photoluminescence excitation, we probe the upper heavy hole exciton manifold and find rapid relaxation to the lower light hole manifold on a 5 ps time scale. State selective excitation allows the preparation of single quantum states in this system. We used this to map the hole spin relaxation pathways between the fine structure sublevels, which have energy splittings incommensurate with either optical or acoustic phonon energies. This reveals a hitherto unexpected hole spin-relaxation channel in these materials.< Réduire
Mots clés en anglais
CdSe
single nanocrystal
Photoluminescence
Photoluminescence excitation
quantum dot
spin relaxation
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