Abstract
We demonstrate a new method to realize the population inversion of a single quantum dot excited by a laser pulse tuned within the neutral exciton phonon sideband. In contrast to the conventional method of inverting a two-level system by performing coherent Rabi oscillation, the inversion is achieved by rapid thermalization of the optically dressed states via incoherent phonon-assisted relaxation. A maximum exciton population of is measured for a laser tuned 0.83 meV to higher energy. Furthermore, the phonon sideband is mapped using a two-color pump-probe technique, with its spectral form and magnitude in very good agreement with the result of path-integral calculations.
- Received 2 September 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.137401
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© 2015 Published by American Physical Society
Viewpoint
Crystal Vibrations Invert Quantum Dot Exciton
Published 30 March 2015
Phonons assist in creating an excitation-dominated state, or population inversion, in a single quantum dot—an effect that could be used to realize single-photon sources.
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