Extreme spin coherence times for long-lived multi-particle spin states in topological order

Prof. Dr. Ferdinand Schmidt-Kaler
Prof. Dr. Dmitry Budker
Dr. Bjoern Lekitsch

With this proposed ‘Startup Excellence Project’ we apply for funding to lay the experimental groundwork to establish extremely long-lived spin states. We plan on realizing spin chains using trapped 40Ca+ - ion spin states, which have a virtually infinite T1 time, however display dephasing induced by magnetic field fluctuations. Within this project we plan to improve over our experimentally demonstrated coherence times of 2.3 seconds by more than an order of magnitude. Extremely long-lived spin states are crucial for future investigations of topological skyrmion states using a digital quantum simulation approach.
Within the proposed project, we envisage to design and implement a three-layer mu-metal chamber for a new experimental setup, which is expected to improve magnetic shielding by an order of magnitude, and combine it with an active magnetic field compensation.
After setting up the new experimental apparatus, we plan to perform detailed characterizations of the improved magnetic field stabilization and measurements of the improved spin coherence times.
The goal of this startup project is to establish extremely long-lived multi-particle spin states and in the development process to also compare ultra-sensitive magnetometers.