1. Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
2. Texas A&M AgriLife Research, Texas A&M University, College Station, Texas 77843-4242, USA
3. Hagler Institute for Advanced Study and Department of Physics and Astronomy, Institute for Quantum Science and Engineering (IQSE), Texas A&M University, College Station, Texas 77843-4242, USA