Schueppert, Klemens

Date:   Friday, May 4, 2018
Time:  11:30
Place:  ETH Zurich, Hönggerberg, HPF G 6
Hosts:  Jonathan Home/Thomas Lutz

Towards fiber-based quantum interfaces with linear ion traps

Klemens Schüppert
Universität Innsbruck, Austria

Single ions in linear traps coupled to optical cavities can form interfaces between flying qubits and stationary qubits with advanced information processing capability. Using fiber-based cavities opens up prospects to reach the strong-coupling regime, enabling protocols with high fidelity and efficiency in long-distance quantum communication. The challenge of this approach is the trade-off between cavity length and ion-fiber distance, because dielectric fibers could be charged and disturb the ions' potential. We developed procedures to adjust these charges on the fiber's dielectric surfaces, allowing us to couple trapped ions to a fiber cavity. Unfortunately, we were not able to stably operate in this regime. But with our setup we determined the amount of surface charges on our fibers. Additionally, using advanced CO2-laser ablation techniques, we optimized fiber mirrors for longer cavities while maintaining the high coupling rate between ion and cavity. Finally, I'll present our new design, which was developed with the aid of these results, to overcome our current limitations.

Hopefully, I'll cover all points sufficiently... In the end it will be a quite informal talk and I'm happy about many questions/discussions.