2018/06/14 by Thomas Chalopin, Chayma Bouazza, Alexandre Evrard +5 · 1 citation
Physics and Astronomy · #quant-ph #cond-mat.quant-gas #physics.atom-ph
paper · pdf · doi:10.1038/s41467-018-07433-1
11 pages, 6 figures
arxiv created 2018/06/14 · arxiv updated 2018/12/07
Coherent superposition states of a mesoscopic quantum object play a major role in our understanding of the quantum to classical boundary, as well as in quantum-enhanced metrology and computing. However, their practical realization and manipulation remains challenging, requiring a high degree of control of the system and its coupling to the environment. Here, we use dysprosium atoms - the most magnetic element in its ground state - to realize coherent superpositions between electronic spin states of opposite orientation, with a mesoscopic spin size J=8. We drive coherent spin states to quantum superpositions using non-linear light-spin interactions, observing a series of collapses and revivals of quantum coherence. These states feature highly non-classical behavior, with a sensitivity to magnetic fields enhanced by a factor 13.9(1.1) compared to coherent spin states - close to the Heisenberg limit 2J=16 - and an intrinsic fragility to environmental noise.