Extending rotational coherence of interacting polar molecules in a spin-decoupled magic trap
Quantum Many Body Systems Division,Max-Planck-Institut für Quantenoptik, Germany
报告摘要：Ultracold polar molecules with strong tunable long-range interaction offer new opportunities for quantum engineering due to their long single-particle lifetime and additional degrees of freedom. One of the important obstacles in this field is the short rotational coherence time of molecules in optical traps limited by the complex coupling between molecular rotations, nuclear spin and trapping light field. In this work, we extend this lifetime by nearly one order of magnitude in a dilute gas of dipolar 23Na40K molecules. By employing a nuclear spin-decoupled magic trap, we minimize first and second order differential light shifts. The latter is achieved by applying a moderate DC electric field that effectively decouples nuclear spin and rotation. As a result, for the first time the dipolar interactions become as strong as the bare single-particle dephasing in a gas of ultra-cold polar molecules. We observe a density-dependent rotational coherence time due to the dipolar interactions. Our work pave the way for robust quantum manipulation of ultra-cold polar molecules.
Dr. Xinyu Luo received his BS (2007) from Harbin Institute of Technology and Ph.D from Institute of Physics, Chinese Academy of Sciences (2013). He worked as a postdoc fellow Tsinghua University (2013-2016), during which he demonstrated deterministic generation of entanglement of 900 atoms by driving a spinor condensate through quantum phase transitions. Since 2016, he has been working as a postdoc fellow in Max-Planck-Institut für Quantenoptik. He is focusing on ultra-cold polar molecular gas in optical lattices and quantum many-body physics with long-range interactions.