2018-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/712081摘要：實驗室發展在超高真空環境中，劈裂新穎材料之剖面，量測材料剖面以及異質結 構間的介面之掃描穿隧能譜的經驗已有十年的時間。本研究計畫，擬運用這項經驗，在 接下來的三年研究執行計畫時間內，在超導物質領域內，量測凝態物理界仍不清楚異於 高溫超導物質(001)表面之電子結構。此高解析度的研究成果，可直接揭發超導體不同層 間之超導電子結構。 以掃描穿隧顯微鏡討論高溫超導物理，長年以來多量測(001)表面穿隧能譜之電子 結構。然而，沿著[001]方向的穿隧能譜之電子結構，是一組平均(100)面和(010)面的電 子結構之研究結果。對於材料結構中，垂直[001]方向超導物質間不同物質層的本質電子 特性，仍是不清楚的問題。利用剖面掃描穿隧能譜量測超導物質異於(001)表面之電子結 構，揭露超導物質間不同物質層的本質電子特性，並進一步討論高溫超導可能形成機 制，是本研究計畫主要的研究動機。 研究計畫中，擬由剖面掃描穿隧能譜探討超導物理三項課題。分別為：超導體的 低溫穿隧能譜、超導體的膺能隙(pseudogap)隨溫度相依的電子能態，以及超導體中準粒 子電子干涉圖騰的探討(quasiparticle interference oscillations)。此研究成果，將對高溫超 導體之形成機制有進一步討論的機會，也將有助於科學家未來尋求效能更好的高溫超導 體。<br> Abstract: Superconductivity is one of the most remarkable observation in physics in the 20th century. Previous STM works were carried out with the c-axis tunneling of high-temperature superconductors. This c-axis tunneling configuration shows an angular average over the ab-plane density of states. However, in layered high-temperature cuprates superconductors, their anisotropic structural, electronic, and superconducting properties attribute to an ambiguous interpretation of tunneling experiments. The tunneling spectra of (001) surfaces therefore could depend on the termination layer and momentum states contribute to the tunneling current. To enable a direct probe of the alternate layer between insulating and superconducting layers in high-temperature cuprates superconductors, the STM measurements from cross-sectional side becomes attracting and important. In my lab, we have the experience of utilizing cross-sectional scanning tunneling spectroscopy to study the electronic property from the cross-sectional view of novel materials for many years. In this new three-year proposal, I would like to take the advantage of this unique technique to explore the unclear issues in the high-temperature superconductor field using the cross-sectional STM. With the measurements from the cross-sectional side, the superconducting electronic characteristic of the CuO2 sheets, the insulating behavior in BiO layers, or the proximity electronic property in CuO chains can be directly and individually investigated. Besides the low-temperature tunneling spectroscopy of individual layers in superconductors, the temperature dependence of the local density of states (discussing scaling properties between psedogap and superconducting gap), and the quasiparticle interference oscillations in the superconducting state will also be studied. A careful assessment of the tunneling junction in cross-sectional STM measurements could be prerequisite to discuss the above ambiguities and provide a reasonable meaningful interpretation of tunneling spectra in high-temperature cuprates superconductors.剖面掃描穿隧能譜高溫超導體超導態Cross-sectional STMSuperconductivitySuperconducting state