超冷基态铷铯极性分子的制备
发布时间：2018-10-20 08:36
【摘要】：研究光与物质相互的相互作用一直是人类认识世界的基本途径。以激光冷却中性原子、原子玻色-爱因斯坦凝聚(BEC)、光学相干和精密光谱方面工作相继获得的Nobel物理学奖为重要里程碑,超冷原子研究开辟了原子分子研究的新天地。自从激光冷却俘获可以被用来操控原子以来,基于超冷原子制备具有更加丰富内在结构的超冷分子成为一个新的挑战,尤其是超冷极性分子。超冷极性分子因其具有的永久电偶极矩、易受外场操控、可调控的各向异性长程偶极-偶极作用等特点使其在精密测量、量子计算、多体问题和超冷化学等方面有着重要的潜在应用。在超冷极性分子研究中,人们尤其是对具有大电偶极矩且稳定的基单态分子感兴趣。基单态分子长的相互作用时间和强的耦合作用能够为实现量子态的可控性,保持良好的相干性提供重要保障。同时,分子具有的多重振转能级结构为量子态的并行运算提供了可能,到目前为止仅有少数一些分子种类可以使用类似原子激光冷却技术实现分子的直接冷却。以超冷原子样品为基础,通过光场或者磁场的缔合是目前制备超冷分子的主要技术手段。本文以制备超冷基单态铷铯极性分子为目标,建立了制备超冷铷铯极性分子的实验平台,通过对激发态高分辨光缔合光谱的研究,构建了一条最佳的制备基单态超冷铷铯极性分子的光学跃迁路径,并在实验上得到了验证,通过使用共振增强双光子电离技术实现了基单态超冷铷铯极性分子的有效探测。本文的主要创新性工作概括如下：一、提出了一种基于共振增强双光子电离技术的测量超冷分子温度的简单快速有效的方法,可以实现分子温度的快速测量,解决了超冷分子温度无法快速估量的问题。二、使用高分辨光缔合光谱对超冷铷铯极性分子目标激发态进行了详细研究,获得了精确的分子常数和势能曲线,为构造基单态超冷铷铯极性分子的光学跃迁路径建立了实验基础。三、在工作二的基础上,实现了超冷基单态铷铯极性分子的制备,并利用共振增强双光子电离技术实现了基单态超冷铷铯极性分子的有效探测,将基于超冷极性分子的应用推进了一步。四、利用斯塔克效应实现了超冷铷铯极性极性分子永久电偶极矩的精确测量,为下一步将要进行的超冷极性分子的外场操控提供了良好的实验基础。
[Abstract]:The study of the interaction between light and matter has been the basic way to understand the world. With the important milestone of laser cooling neutral atom, atomic Bose-Einstein condensate (BEC), optical coherence and precise spectrum, the Nobel physics prize has been won one after another, and the study of ultra-cold atom has opened a new field of atomic and molecular research. Since laser cooling trapping can be used to manipulate atoms, it has become a new challenge to prepare ultracold molecules based on ultracold atoms with more abundant intrinsic structures, especially ultra-cold polar molecules. Because of its permanent electric dipole moment, easy to be controlled by external field and adjustable anisotropic long range dipole-dipole interaction, ultracold polar molecules are used in precise measurement, quantum calculation, etc. Multibody problems and supercooled chemistry have important potential applications. In the study of ultracold polar molecules, people are especially interested in the fundamental monolayers with large electric dipole moment and stability. The long interaction time and strong coupling can provide an important guarantee for realizing the controllability of quantum states and maintaining good coherence. At the same time, the multi-vibrational energy level structure provides the possibility for parallel operation of quantum states. Up to now, only a few kinds of molecules can be cooled directly by similar atomic laser cooling techniques. Based on the supercooled atomic sample, the association of light field or magnetic field is the main technique for preparing ultracold molecules. In this paper, an experimental platform for the preparation of supercooled rubidium cesium polar molecules was established, and the excited state high resolution photoassociation spectra were studied. An optimal optical transition path for preparing base supercooled rubidium cesium polar molecules was constructed and verified experimentally. The effective detection of the base single state supercooled rubidium cesium polar molecules was realized by resonance enhanced two-photon ionization technique. The main innovative work of this paper is summarized as follows: firstly, a simple, fast and effective method for measuring the temperature of super-cooled molecules based on resonance enhanced two-photon ionization technique is proposed, which can realize the rapid measurement of molecular temperature. It solves the problem that the temperature of ultracold molecules can not be measured quickly. Secondly, the excited states of polar molecular targets of ultra-cooled rubidium and cesium have been studied in detail by using high resolution photoassociation spectroscopy, and the exact molecular constants and potential energy curves have been obtained. The experimental basis is established for constructing the optical transition path of the base supercooled rubidium cesium polar molecule. Thirdly, on the basis of work 2, the preparation of supercooled rubidium cesium polar molecule is realized, and the effective detection of base single state rubidium cesium polarity molecule is realized by resonance enhanced two-photon ionization technique. The application based on ultracold polar molecules is further promoted. Fourthly, the accurate measurement of permanent electric dipole moment of ultracold rubidium cesium polarity molecule is realized by using Stark effect, which provides a good experimental basis for the external field control of ultracold polar molecule to be carried out in the next step.
【学位授予单位】：山西大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O561
本文编号：2282622
[Abstract]:The study of the interaction between light and matter has been the basic way to understand the world. With the important milestone of laser cooling neutral atom, atomic Bose-Einstein condensate (BEC), optical coherence and precise spectrum, the Nobel physics prize has been won one after another, and the study of ultra-cold atom has opened a new field of atomic and molecular research. Since laser cooling trapping can be used to manipulate atoms, it has become a new challenge to prepare ultracold molecules based on ultracold atoms with more abundant intrinsic structures, especially ultra-cold polar molecules. Because of its permanent electric dipole moment, easy to be controlled by external field and adjustable anisotropic long range dipole-dipole interaction, ultracold polar molecules are used in precise measurement, quantum calculation, etc. Multibody problems and supercooled chemistry have important potential applications. In the study of ultracold polar molecules, people are especially interested in the fundamental monolayers with large electric dipole moment and stability. The long interaction time and strong coupling can provide an important guarantee for realizing the controllability of quantum states and maintaining good coherence. At the same time, the multi-vibrational energy level structure provides the possibility for parallel operation of quantum states. Up to now, only a few kinds of molecules can be cooled directly by similar atomic laser cooling techniques. Based on the supercooled atomic sample, the association of light field or magnetic field is the main technique for preparing ultracold molecules. In this paper, an experimental platform for the preparation of supercooled rubidium cesium polar molecules was established, and the excited state high resolution photoassociation spectra were studied. An optimal optical transition path for preparing base supercooled rubidium cesium polar molecules was constructed and verified experimentally. The effective detection of the base single state supercooled rubidium cesium polar molecules was realized by resonance enhanced two-photon ionization technique. The main innovative work of this paper is summarized as follows: firstly, a simple, fast and effective method for measuring the temperature of super-cooled molecules based on resonance enhanced two-photon ionization technique is proposed, which can realize the rapid measurement of molecular temperature. It solves the problem that the temperature of ultracold molecules can not be measured quickly. Secondly, the excited states of polar molecular targets of ultra-cooled rubidium and cesium have been studied in detail by using high resolution photoassociation spectroscopy, and the exact molecular constants and potential energy curves have been obtained. The experimental basis is established for constructing the optical transition path of the base supercooled rubidium cesium polar molecule. Thirdly, on the basis of work 2, the preparation of supercooled rubidium cesium polar molecule is realized, and the effective detection of base single state rubidium cesium polarity molecule is realized by resonance enhanced two-photon ionization technique. The application based on ultracold polar molecules is further promoted. Fourthly, the accurate measurement of permanent electric dipole moment of ultracold rubidium cesium polarity molecule is realized by using Stark effect, which provides a good experimental basis for the external field control of ultracold polar molecule to be carried out in the next step.
【学位授予单位】：山西大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O561
【参考文献】
相关期刊论文 前1条
1 金丽;冯国胜;武寄洲;马杰;汪丽蓉;肖连团;贾锁堂;;The laser-intensity dependence of the photoassociation spectrum of the ultracold Cs_2(6S_(1/2) + 6P_(1/2))0_u~+ long-range molecular state[J];Chinese Physics B;2013年08期
，本文编号：2282622
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