Hannover 2020 – wissenschaftliches Programm
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Q 33.2: Vortrag
Mittwoch, 11. März 2020, 14:30–14:45, e001
Dynamical decoupling of anisotropic interacting spin ensembles — •Pablo Cova Fariña1, Benjamin Merkel1, Penghong Yu1, Natalia Herrera Valencia1, and Andreas Reiserer1,2 — 1Max Planck Institute of Quantum Optics, Hans-Kopfermann-Straße 1, 85748 Garching bei München, Germany — 2Munich Center for Quantum Science and Technology (MCQST), Ludwig-Maximilians-Universität München, 80799 München, Germany
Rare-earth doped crystals are explored for quantum memory and quantum sensing applications because they can exhibit long coherence times of both spin and optical transitions. Among the rare earths, Erbium stands out for two reasons. First, its optical transition is at a telecom wavelength. Second, the large magnetic moment of its electronic spin, with effective g factors up to 16, renders it a possible candidate for quantum magnetometers with high sensitivity. Unfortunately, this large and anisotropic effective g factor comes at the prize of strong spin-spin interactions that often limit the achievable coherence time. In this work, we explore how to overcome this challenge in Er:YSO crystals using dynamical decoupling (DD). With a simple spin echo, we observe an increase of the coherence time by an order of magnitude. However, using standard DD sequences, such as XY-8, does not bring a much larger improvement, as the coherence in our 10 ppm doped crystal is limited by instantaneous diffusion. We therefore analyze the effect of novel DD sequences, both from an experimental and a theoretical point of view, and show that they can outperform standard DD sequences for anisotropic and strongly interacting spin ensembles.