Dresden 2003 – scientific programme

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HL: Halbleiterphysik

HL 49: Poster II

HL 49.68: Poster

Thursday, March 27, 2003, 16:30–19:00, HSZ/P2

Biexcitons in Coupled Quantum Dots as a Source of Entangled Photons — •Oliver Gywat, Guido Burkard, and Daniel Loss — Departement für Physik und Astronomie, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel, Schweiz

We study biexcitonic states in two tunnel-coupled semiconductor quantum dots and show that such systems provide the possibility to produce polarization-entangled photons or spin-entangled electrons that are spatially separated at production. We distinguish between the various spin configurations and calculate the low-energy biexciton spectrum using the Heitler-London approximation as a function of magnetic and electric fields. The oscillator strengths for the biexciton recombination involving the sequential emission of two photons are calculated. The entanglement of the photon polarizations resulting from the spin configuration in the biexciton states is quantified as a function of the photon emission angles. Ref.: O. Gywat, G. Burkard, and D. Loss, Phys. Rev. B 65, 205329 (2002).