Research projects

	Sources of entangled photon pairs Most quantum information experimens depend on strong sources for entangled photons. We try to improve the entanglement quality, brightness and usability of such sources based on parametric down conversion.
	Quantum state estimation Optical quantum communication and measurements require often complete quantum state estimation. Our minimal polarimeter topologies allow efficient tomography of single and multiphoton states.
	Quantum cryptography A practical application of quantum information ideas to establish a secure communication channel. Our experiments implement entanglemend-based cryptography protocols via a free-space optical link.
	Colloidal quantum dots Interaction of light with matter on a single quanta level can be studied using colloidal quantum dots in a solid transparent matrix. We explore such dots for their suitability for quantum information processing.
	Multiphoton entanglement Complex quantum information protocols can be based on multiphoton entanglement. We investigate preparation of such states via parametric down conversion with femtosecond pump pulses.
	Single atom quantum interfaces One of the cleanest quantum information storage systems are internal degrees of freedom of single atoms. We want to understand the basics of atom-light interaction for future quantum interfaces.