Conditional Dynamics of Interacting Quantum Dots
Lucio Robledo,1
Jeroen Elzerman,1
Gregor Jundt,1
Mete Atatüre,2
Alexander Högele,1
Stefan Fält,1
Atac Imamoglu1*
Conditional quantum dynamics, where the quantum state of one system controls the outcome of measurements on another quantum system, is at the heart of quantum information processing. We demonstrate conditional dynamics for two coupled quantum dots, whereby the probability that one quantum dot makes a transition to an optically excited state is controlled by the presence or absence of an optical excitation in the neighboring dot. Interaction between the dots is mediated by the tunnel coupling between optically excited states and can be optically gated by applying a laser field of the right frequency. Our results represent substantial progress toward realization of an optically effected controlled–phase gate between two solid-state qubits.
1 Institute of Quantum Electronics, Eidgenössische Technische Hochschule (ETH)–Zürich, CH-8093 Zürich, Switzerland.
2 Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
* To whom correspondence should be addressed. E-mail: imamoglu{at}phys.ethz.ch
