準一維帶自旋玻色氣體實驗之建構

Experiments toward realizing a quasi-1D spinor bose gas

林玟辰(Wen-Chen Lin)

指導教授 ： 林俊達

國立臺灣大學/理學院/物理研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01640

摘要

強關聯系統可由一維空間下帶有交互作用的粒子形成。若能引入自
旋操控的技術，就可以探討帶自旋的強關聯系統。在這篇論文中，我
將會介紹我們在一維空間下，對於強交互作用之帶自旋玻色氣體的研
究進展。我們首先在交叉光阱中製造銣原子玻色愛因斯坦凝結(BEC)。
過程中，我們利用外加磁場和微波來調整銣原子的自旋態。接著，我
們將BEC 轉移到二維光晶格中並且觀察到二維超流體與莫特絕原體之
間的相變。另一方面，我們的二維光晶格本身是由許多一維位能井組
成的陣列，因此我們利用二維光晶格來產生一維位能井。在目前架設
的一維位能井中，我們透過量測三體碰撞損失率，來觀察到由粒子交
互作用造成的三體關聯性(three-body correlation) 降低。我們目前的玻色氣體處於弱交互作用區間，但已經很接近我們想達到的強交互作用
區間。

關鍵字

冷原子 ； 玻色愛因斯坦凝結 ； 二維光晶格 ； 一維玻色氣體 ； 帶自旋玻色氣體

並列摘要

A strongly correlated system can be constructed by interacting quantum
particles confined in one dimension. Including a spin manipulating technique,
one can investigate spin dynamics of such system. In this thesis, I
will present our experimental efforts toward studying the quantum dynamics
of strongly interacting quasi-1D spinor Bose gas. In our experiment, we produced
a rubidium Bose-Einstein condensate (BEC) in a crossed optical dipole
trap (XODT), and tailored the spin population of the condensate by applying
external magnetic fields and microwaves. Following that the condensate was
further loaded into a 2D optical lattice, and the quantum phase transition between
superfluid and insulator phases was observed.On the other hand, the
2D optical lattice is an array of quasi-1D tubular potentials, so we formed
quasi-1D potentials by means of a 2D optical lattice. In the present quasi-1D
potential tubes, the suppression of three body correlation due to interaction
has been observed by measuring the 3-body loss rates. Thus far, our bose
gas is in the Thomas-Fermi (weakly interacting) regime and is reaching to a
Tonks Girardeau regime.

並列關鍵字

Spinor bose gas ； Bose-Einstein condensate ； 1D bose gas ； 2D optical lattice ； Tonks-Girardeau gas

參考文獻

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23–30, 2005.

[5] Frank Deuretzbacher, Klaus Fredenhagen, Daniel Becker, Kai Bongs, Klaus Sengstock,

and Daniela Pfannkuche. Exact solution of strongly interacting quasi-onedimensional

[7] Ming-Shien Chang. Coherent Spin Dynamics of a Spin-1 Bose-Einstein Condensate.