Quantum Optics Seminar by Oliver Benson

Photons as ’glue’ for dissimilar quantum systems 

A quantum hybrid system can be defined as consisting of two dissimilar physical systems that share a joint quantum state. Aside from being a fundamentally interesting object, a few applications, such as quantum information processors (quantum computers, quantum repeaters), have been suggested. The only way to bring two distant systems in a joint quantum state is to perform measurements on photons.
Here we report on different photon sources, which could be part of a quantum hybrid architecture [1] or which could provide the ‘glue’ for dissimilar quantum systems. We consider narrow-band photon-pair sources [2] based on paramteric down-conversion and on-demand solid state sources, such as semiconductor quantum dots [3] or defect centers in diamond [4].The talk concerns an introduction to the different systems, the integration of stable emitters as reliable sources, and the non-linear conversion of their photons, e.g. to the telecom band. Future directions will be discussed. 

[1] “Assembly of hybrid photonic architectures from nanophotonic constituents“, O. Benson, Nature 480, 193-199 (2011)
[2] “Bright source of indistinguishable photons based on cavity-enhanced parametric down-conversion utilizing the cluster effect”, A. Ahlrichs, O. Benson, to be published in APL
[3] “Highly Entangled Photons from Hybrid Piezoelectric-Semiconductor Quantum Dot Devices“, R. Trotta, J.S. Wildmann, E. Zallo, O.G. Schmidt, and A. Rastelli, Nano Lett. 14, 3439-3444 (2014)
[4] “Three-dimensional quantum photonic elements based on single nitrogen vacancy-centres in laser-written microstructures“, A.W. Schell, J. Kaschke, J. Fischer, R. Henze, J. Wolters, M. Wegener, M, and O. Benson, Scientific Reports 3, (2013)