Nonlocal state swapping of polar molecules in bilayers
Nonlocal state swapping of polar molecules in bilayers
复制标题
双层中极性分子的非局域状态交换
DOI：
10.1103/physreva.84.061605
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发表时间：
2011
影响因子：
2.9
通讯作者：
L. Santos
中科院分区：
文献类型：
--
作者：
A. Pikovski;M. Klawunn;A. Recati;L. Santos
在超冷极性分子气体中观察到显著的偶极效应通常需要强的外部电场来使分子稳定。我们表明，即使在没有显着极化的情况下，偶极效应也可能在双层中极性分子的物理学中发挥至关重要的作用，前提是每层中的分子最初都以不同的旋转状态准备。然后，层间偶极相互作用导致不同层中的分子之间的旋转状态的非局部交换，即使对于弱的施加电场。由于偶极-偶极相互作用的层间散射导致交换速率对密度、温度、层间间距和布居不平衡的非平凡依赖。对于像KRb这样的反应性分子，化学复合立即跟随非局域交换，即使在远高于量子简并的温度下也会主导损失，因此可以在当前的实验条件下观察到。PACS编号：67.85。d，34.50.Cx新一代的实验已经开始探索偶极气体的显着的新物理，其中偶极-偶极相互作用起着关键作用[1]。这些相互作用是长程的和各向异性的，不同于到目前为止在超冷原子物理学中占主导地位的短程各向同性相互作用。极性分子由于其大的电偶极矩，有望为量子气体提供迷人的新场景。最近在JILA [2]进行的KRb振转态和超精细态的制备和控制实验为极性分子的简并量子气体开辟了新的前景。不幸的是，由于KRb的反应特性，化学复合到目前为止还无法达到量子简并[3]。然而，部分极化的
The observation of significant dipolar effects in gases of ultra-cold polar molecules typically demands a strong external electric field to polarize the molecules. We show that even in the absence of a significant polarization, dipolar effects may play a crucial role in the physics of polar molecules in bilayers, provided that the molecules in each layer are initially prepared in a different rotational state. Then, inter-layer dipolar interactions result in a non-local swap of the rotational state between molecules in different layers, even for weak applied electric fields. The inter-layer scattering due to the dipole-dipole interaction leads to a non-trivial dependence of the swapping rate on density, temperature, inter-layer spacing, and population imbalance. For reactive molecules like KRb, chemical recombination immediately follows a non-local swap and dominates the losses even for temperatures well above quantum degeneracy, and could be hence observed under current experimental conditions. PACS numbers: 67.85.-d, 34.50.Cx A new generation of experiments has started to explore the remarkable novel physics of dipolar gases, in which dipole-dipole interactions play a key role [1]. These interactions, being long-range and anisotropic, differ from the short-range isotropic interactions which have dominated up to now ultra-cold atomic physics. Polar molecules are expected to provide fascinating new scenarios for quantum gases due to their large electric dipole moments. Recent experiments on preparation and control of ro-vibrational and hyperfine states of KRb at JILA [2] open new perspectives towards a degenerate quantum gas of polar molecules. Unfortunately chemical recombination due to the reactive character of KRb has up to now prevented to reach quantum degeneracy [3]. However, dipolar interactions between partially polarized