近年在自旋電子領域中非線性磁性結構為熱門研究議題，具備成為新一代磁存儲與自旋傳輸元件的潛力。在低維度的磁性材料薄膜系統通常具備此種特殊磁性結構，在本次研究雙層錳成長在Ag(111)系統中，發現在二層錳具有兩種不同種類的非線性磁性結構，並且此種磁性結構差異可以由二層錳成長在單層錳上的原子結構差異區分。透過掃描穿隧式顯微鏡(Scanning Tunneling Spectroscopy, STM)量測，二層錳在單層錳上具有呈假晶(pseudomorphic)成長的DLS-Mn與因材料表面應變釋放(strain relief)形成具有週期性重構結構(reconstructed structure)的DLR-Mn兩種原子結構。
經由自旋極化掃描穿隧式顯微鏡(Spin-polarized STM, SP-STM)進行表面磁性結構量測，在單層錳成長在Ag(111)具有先前研究發現的特殊非線性結構，120° Néel State [1]，在此磁性結構中的自旋方向皆為in-plane方向，運用此種自旋結構，我們可以解析探針自旋極化方向在in-plane方向角度的變化，經由分析一、二層錳在使用不同自旋極化方向探針的自旋圖紋(spin texture)差異，與進行SP-STM模擬檢驗，我們最終發現此系統磁性結構由海森堡交換耦合作用力（Heisenberg exchange interaction) 主導，在DLR-Mn形成spin spiral state，而在DLS -Mn形成spin spiral state與反鐵磁結構組成的特殊磁性結構，conical spin spiral state。

In recent years, nonlinear magnetic structures have been a popular research topic in the field of spintronics, showing potential for being utilized in next-generation magnetic storage and spin transport devices. Such unique magnetic structures are often observed in low-dimensional magnetic thin film systems.In this study, it was discovered that bilayer Mn grown on the Ag(111) system exhibits two distinct types of non-colinear magnetic structures, and these differences in magnetic structure can be distinguished by the atomic structure of the bilayer Mn grown on monolayer Mn. Through scanning tunneling microscopy (STM) measurements, it was observed that the bilayer Mn on monolayer Mn exhibits two atomic structures: DLS-Mn, which grows in a pseudomorphic manner, and DLR-Mn, which forms a periodically reconstructed structure due to material surface strain relaxation.
By analyzing the magnetic structures using spin-polarized STM, it was found that the monolayer Mn grown on Ag(111) exhibits a previously discovered special non-colinear structure, the 120° Néel state [1], in which the spin orientation are all in-plane. By utilizing this spin structure, the variations in the probe spin polarization direction in the in-plane direction were analyzed. By comparing the spin patterns obtained with probes of different spin polarization directions and performing SP-STM simulations, it was ultimately discovered that the magnetic structure in this system is governed by Heisenberg exchange interactions. In DLR-Mn, a spin spiral state is formed, while in DLS-Mn, a unique magnetic structure consisting of a spin spiral state and antiferromagnetic structure is formed, known as a conical spin spiral state.

摘要I
Abstract II
致謝III
目錄IV
圖目錄VI
表目錄XV
第一章簡介(Introduction) 1
1.1 動機. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 非線性磁性結構. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 文獻回顧. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.1 DL Mn/W(110) 系統. . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.2 ML Mn/W(001) 系統. . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3.3 DL Fe/Ir(111) 系統. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.4 DL Fe/Cu(111) 系統. . . . . . . . . . . . . . . . . . . . . . . . . . . 15
第二章實驗儀器與工作原理(Experiment apparatus) 16
2.1 真空系統. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.1 超高真空. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
IV
2.1.2 真空抽氣系統. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.1.3 真空壓力計. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.1.4 殘餘氣體分析儀. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.1.5 電子束蒸鍍槍. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.2 掃描穿隧式顯微鏡. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.1 量子穿隧效應. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2.2 巴丁穿隧理論. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.2.3 掃描穿隧能譜. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.2.4 自旋極化掃描穿隧式顯微鏡. . . . . . . . . . . . . . . . . . . . . . 30
2.2.5 取樣模式. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
第三章實驗結果與討論(Experiment Results and Discussion) 34
3.1 製備樣品. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.1.1 樣品清理. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.1.2 薄膜成長. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2 DL Mn/Ag(111) 系統. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2.1 Pseudomorphic DL Mn/Ag(111) . . . . . . . . . . . . . . . . . . . . . 39
3.2.2 Reconstructed DL Mn/Ag(111) . . . . . . . . . . . . . . . . . . . . . 42
第四章實驗結果與討論(Summary) 47
參考文獻(Reference) 48
Appendix 52

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