Lutz, Thomas

Date:  Tuesday, December 19, 2017
Time:  11:00
Place:  ETH Zurich, Hönggerberg, HPF G 6
Host:  Jonathan Home

Engineered impurity-doped materials for Quantum Information Processing applications -nano-structures and disordered materials

Thomas Lutz
University of Calgary, Canada

I will discuss various ways to extend population lifetimes and coherence times of solid-state emitters. I focus on rare-earth-ion doped host materials and silicon vacancy centers in diamond, both of which are used for applications in quantum information processing and quantum communications.

One approach investigates the possibility to suppress lattice vibrations that cause decoherence and population relaxation by engineering the phonon density of states through nano-structuring of the emitter's host material. Towards this end we studied different materials and methods to obtain the desired nano-materials. Using various optical spectroscopic methods, we showed that population dynamics can indeed be influenced by modifying the structure of the surrounding host material. For the silicon vacancy centers I will briefly discuss opportunities arising from the coupling to micro-cavities in diamond and present initial results.

As a second approach, we studied rare-earth-ions in disordered host materials. We showed with the example of an erbium doped fiber that such materials can indeed feature better properties, specifically longer population lifetimes, than the commonly used bulk crystals. This made it possible to use this medium for successful proof of principle experiments demonstrating a multimode quantum memory that operates within the convenient telecom band (around 1550 nm wavelength).