arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1406.2668physics.chem-phphysics.atom-ph
收藏

氧超转子的相干自旋-转动动力学

Coherent spin-rotational dynamics of oxygen super rotors

Alexander A. Milner, Aleksey Korobenko, Valery Milner

摘要:

我们使用状态和时间分辨相干拉曼光谱来研究超高旋转态氧分子的旋转动力学。虽然可以通过将气体温度增加到1500 K来达到高达$N \approx 50$的旋转量子数,但是低的布居水平和气体密度导致相应弱的光学响应。通过光学离心机旋转O $_2$分子,我们有效地激发极端的旋转态与$N\leqslant 109$在高密度室温系综。快速的分子旋转导致产生的旋转波包对碰撞的鲁棒性增强,使我们能够观察到弱自旋旋转耦合在氧的相干旋转动力学的影响。由于碰撞的自旋旋转相干的衰减率测量作为分子角动量的函数,并解释在一般的标度律。我们发现,在高值的$N$,旋转退相干的氧是比以前研究的非磁性氮分子快得多。这可能表明在顺磁气体中有一种不同的转动弛豫机制。

英文摘要:

We use state- and time-resolved coherent Raman spectroscopy to study the rotational dynamics of oxygen molecules in ultra-high rotational states. While it is possible to reach rotational quantum numbers up to $N \approx 50$ by increasing the gas temperature to 1500 K, low population levels and gas densities result in correspondingly weak optical response. By spinning O$_2$ molecules with an optical centrifuge, we efficiently excite extreme rotational states with $N\leqslant 109$ in high-density room temperature ensembles. Fast molecular rotation results in the enhanced robustness of the created rotational wave packets against collisions, enabling us to observe the effects of weak spin-rotation coupling in the coherent rotational dynamics of oxygen. The decay rate of spin-rotation coherence due to collisions is measured as a function of the molecular angular momentum and explained in terms of the general scaling law. We find that at high values of $N$, the rotational decoherence of oxygen is much faster than that of the previously studied non-magnetic nitrogen molecules. This may suggest a different mechanism of rotational relaxation in paramagnetic gases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑