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HL: Fachverband Halbleiterphysik
HL 19: Quantum Dots and Wires: Optics I
HL 19.3: Talk
Tuesday, March 19, 2024, 10:00–10:15, EW 202
Stimulated excitation and coherent control of dark exciton state population in a quantum dot — •Florian Kappe1, René Schwarz1, Yusuf Karli1, Thomas Bracht2, Saimon Covre da Silva3, Armando Rastelli3, Vikas Remesh1, Doris Reiter2, and Gregor Weihs1 — 1Institute für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria — 2Condensed Matter Theory, Department of Physics, TU Dortmund, Dortmund, Germany — 3Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Linz, Austria
Semiconductor quantum dots, with their capability of confining charge carriers and various spin configurations resulting from it, can be regarded as a highly versatile platform for generating non-classical light. While the generation of single photons or entangled photon pairs from quantum dots utilizes the so-called bright excitons and biexcitons respectively, quantum dots can also host optically dark excitons. Such states are optically inactive due to the spin-selection rules. Due to their longer coherence times, a direct and coherent optical excitation and control of dark states are of great interest in modern quantum information protocols [1]. In this work we demonstrate a stimulated excitation and coherent control of the dark exciton population via the biexciton state in a GaAs/AlGaAs quantum dot in presence of an in-plane magnetic field. The versatility of our scheme allows not only a deterministic preparation, but storage and a temporal retrieval of the dark state population, giving rise to a programmed single photon/photon pair emission.
Keywords: quantum dots; dark exciton states; single photons; entangled photons