2024-01-18 ライス大学
◆従来の1/20秒の量子状態を30倍に延長する成功は、量子技術の発展に向けた新たな洞察を提供し、超冷却分子を利用した新しい実験系の構築に貢献します。
＜関連情報＞
- https://news.rice.edu/news/2024/rice-research-opens-new-arena-study-quantum-interactions
- https://www.nature.com/articles/s41567-023-02328-5
超低温極性分子の気体におけるセカンドスケールの回転コヒーレンスと双極子相互作用 Second-scale rotational coherence and dipolar interactions in a gas of ultracold polar molecules
Philip D. Gregory,Luke M. Fernley,Albert Li Tao,Sarah L. Bromley,Jonathan Stepp,Zewen Zhang,Svetlana Kotochigova,Kaden R. A. Hazzard & Simon L. Cornish
Nature Physics Published:17 January 2024
DOI:https://doi.org/10.1038/s41567-023-02328-5
Abstract
Ultracold polar molecules combine a rich structure of long-lived internal states with access to controllable long-range anisotropic dipole–dipole interactions. In particular, the rotational states of polar molecules confined in optical tweezers or optical lattices may be used to encode interacting qubits for quantum computation or pseudo-spins for simulating quantum magnetism. As with all quantum platforms, the engineering of robust coherent superpositions of states is vital. However, for optically trapped molecules, the coherence time between rotational states is typically limited by inhomogeneous differential light shifts. Here we demonstrate a rotationally magic optical trap for 87Rb133Cs molecules that supports a Ramsey coherence time of 0.78(4) s in the absence of dipole–dipole interactions. This is estimated to extend to >1.4 s at the 95% confidence level using a single spin-echo pulse. In our trap, dipolar interactions become the dominant mechanism by which Ramsey contrast is lost for superpositions that generate oscillating dipoles. By changing the states forming the superposition, we tune the effective dipole moment and show that the coherence time is inversely proportional to the strength of the dipolar interaction. Our work unlocks the full potential of the rotational degree of freedom in molecules for quantum computation and quantum simulation.
