Persistent Inter-Excitonic Quantum Coherence in CdSe Quantum Dots.
The creation and manipulation of quantum superpositions is a fundamental goal for the development of materials with novel optoelectronic properties. In this letter, we report persistent (~80 fs lifetime) quantum coherence between the 1S and 1P excitonic states in zinc-blende colloidal CdSe quantum dots at room temperature, measured using Two-Dimensional Electronic Spectroscopy. We demonstrate that this quantum coherence manifests as an intradot phenomenon, the frequency of which depends on the size of the dot excited within the ensemble of QDs. We model the lifetime of the coherence and demonstrate that correlated interexcitonic fluctuations preserve relative phase between excitonic states. These observations suggest an avenue for engineering long-lived interexcitonic quantum coherence in colloidal quantum dots.
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Justin R
JR
Caram
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Haibin
H
Zheng
Graduate Program in the Biophysical Sciences, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, IL 60637.
Peter D
PD
Dahlberg
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Brian S
BS
Rolczynski
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Graham B
GB
Griffin
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Andrew F
AF
Fidler
Department of Chemistry, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Dmitriy S
DS
Dolzhnikov
Department of Chemistry, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Dmitri V
DV
Talapin
Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Gregory S
GS
Engel
Coherent Dynamics; Semiconducting Nanocrystals; Two dimensional spectroscopy