September 2005: Coupled InAs Quantum dots

Two quantum dots can be stacked on top of each other in the vertical direction using self-assembly during molecular beam epitaxy. This has been demonstrated by Brian Gerardot in the group of Pierre Petroff at the University of California Santa Barbara. The quantum dots show atom-like sharp emission lines at near infrared wavelengths. For the first time we studied the properties of individual complezes formed by two dots in very close proximity hoping to observe the first signature of quantum correlations between emitted photons. The observed correlations can be understood in a classical way, but it became clear that: 1) the tunnel energy between asymetric dots is smaller than that between two symmetric dots 2) extended wetting layer states may form an important intermediate state that enables energy transfer between the two quantum dots.

"Photon Statistics from Coupled Quantum Dots" Brian D. Gerardot, Stefan Strauf, Michiel J. A. de Dood, Andrey M. Bychkov, Antonio Badolato, Kevin Hennessy, Evelyn L. Hu, Dirk Bouwmeester, and Pierre M. Petroff, Phys. Rev. Lett. 95 137403 (2005) PDF (651 kB)