Exciton superposition states in CdSe nanocrystals measured using broadband two-dimensional electronic spectroscopy.
Coherent superpositions among eigenstates are of interest in fields as diverse as photosynthesis and quantum computation. In this report, we used two-dimensional electronic spectroscopy (2D ES) to measure the decoherence time of a superposition of the two lowest-energy excitons in colloidal CdSe nanocrystals (cubic phase) in solution at room temperature. In the electron-hole representation, the quantum coherence is, remarkably, a twelve-particle correlation. By comparing the measured 2D ES to simulations, we also explored the effects of inhomogeneous broadening and examined the spectroscopic signatures of biexcitons.
Department of Chemistry and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George Street, Toronto, Ontario, M5S 3H6 Canada.
Daniel B
DB
Turner
Yasser
Y
Hassan
Gregory D
GD
Scholes
D019187:Cadmium Compounds / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D011789:Quantum Theory; D018036:Selenium Compounds / Q000737:chemistry*; D013057:Spectrum Analysis; D013696:Temperature
D019187:Cadmium Compounds; D003102:Colloids; D018036:Selenium Compounds; C058667:cadmium selenide