超冷基態(tài)銣銫極性分子的制備
發(fā)布時間：2018-10-20 08:36
【摘要】：研究光與物質(zhì)相互的相互作用一直是人類認識世界的基本途徑。以激光冷卻中性原子、原子玻色-愛因斯坦凝聚(BEC)、光學相干和精密光譜方面工作相繼獲得的Nobel物理學獎為重要里程碑,超冷原子研究開辟了原子分子研究的新天地。自從激光冷卻俘獲可以被用來操控原子以來,基于超冷原子制備具有更加豐富內(nèi)在結(jié)構(gòu)的超冷分子成為一個新的挑戰(zhàn),尤其是超冷極性分子。超冷極性分子因其具有的永久電偶極矩、易受外場操控、可調(diào)控的各向異性長程偶極-偶極作用等特點使其在精密測量、量子計算、多體問題和超冷化學等方面有著重要的潛在應(yīng)用。在超冷極性分子研究中,人們尤其是對具有大電偶極矩且穩(wěn)定的基單態(tài)分子感興趣。基單態(tài)分子長的相互作用時間和強的耦合作用能夠為實現(xiàn)量子態(tài)的可控性,保持良好的相干性提供重要保障。同時,分子具有的多重振轉(zhuǎn)能級結(jié)構(gòu)為量子態(tài)的并行運算提供了可能,到目前為止僅有少數(shù)一些分子種類可以使用類似原子激光冷卻技術(shù)實現(xiàn)分子的直接冷卻。以超冷原子樣品為基礎(chǔ),通過光場或者磁場的締合是目前制備超冷分子的主要技術(shù)手段。本文以制備超冷基單態(tài)銣銫極性分子為目標,建立了制備超冷銣銫極性分子的實驗平臺,通過對激發(fā)態(tài)高分辨光締合光譜的研究,構(gòu)建了一條最佳的制備基單態(tài)超冷銣銫極性分子的光學躍遷路徑,并在實驗上得到了驗證,通過使用共振增強雙光子電離技術(shù)實現(xiàn)了基單態(tài)超冷銣銫極性分子的有效探測。本文的主要創(chuàng)新性工作概括如下：一、提出了一種基于共振增強雙光子電離技術(shù)的測量超冷分子溫度的簡單快速有效的方法,可以實現(xiàn)分子溫度的快速測量,解決了超冷分子溫度無法快速估量的問題。二、使用高分辨光締合光譜對超冷銣銫極性分子目標激發(fā)態(tài)進行了詳細研究,獲得了精確的分子常數(shù)和勢能曲線,為構(gòu)造基單態(tài)超冷銣銫極性分子的光學躍遷路徑建立了實驗基礎(chǔ)。三、在工作二的基礎(chǔ)上,實現(xiàn)了超冷基單態(tài)銣銫極性分子的制備,并利用共振增強雙光子電離技術(shù)實現(xiàn)了基單態(tài)超冷銣銫極性分子的有效探測,將基于超冷極性分子的應(yīng)用推進了一步。四、利用斯塔克效應(yīng)實現(xiàn)了超冷銣銫極性極性分子永久電偶極矩的精確測量,為下一步將要進行的超冷極性分子的外場操控提供了良好的實驗基礎(chǔ)。
[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.
【學位授予單位】：山西大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：O561
本文編號：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.
【學位授予單位】：山西大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：O561
【參考文獻】
相關(guān)期刊論文 前1條
1 金麗;馮國勝;武寄洲;馬杰;汪麗蓉;肖連團;賈鎖堂;;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
，本文編號：2282622
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