We optically probe and electrically control a single artificial molecule containing a well defined number of electrons. Charge and spin dependent inter-dot quantum couplings are probed optically by adding a single electron-hole pair and detecting the emission from negatively charged exciton states. Coulomb and Pauli blockade effects are directly observed and hybridization and electrostatic charging energies are independently measured. The inter-dot quantum coupling is confirmed to be mediated predominantly by electron tunneling. Our results are in excellent accord with calculations that provide a complete picture of negative excitons and few electron states in quantum dot molecules.
@article{arxiv.cond-mat/0604659,
title = {Optically Probing Spin and Charge Interactions in an Tunable Artificial Molecule},
author = {H. J. Krenner and E. C. Clark and T. Nakaoka and M. Bichler and C. Scheurer and G. Abstreiter and J. J. Finley},
journal= {arXiv preprint arXiv:cond-mat/0604659},
year = {2007}
}
Comments
shortened version: 6 pages, 3 figures, 1 table, to appear in Phys. Rev. Lett