以極化飛秒光譜研究Y1-xCaxBa2Cu3O7-δ薄膜之各向異性超快動力學

Abstract

釔鋇銅氧高溫超導材料，在過摻雜區域中的偽能隙的分佈情形至今尚未有明確的定論。在本論文當中，利用自行發展的極化飛秒激發探測光譜系統；配合實驗室具有，成長軸向解析之高品質(100)與(001)Y1-xCaxBa2Cu3O7-δ薄膜技術之能力，使我們可以量測在不同溫度下，沿著各個軸向的薄膜瞬時反射率的變化。透過分析在不同溫度下，瞬時反射率與載子弛緩時間的變化情形，我們可以得到在過摻雜高溫超導薄膜上，沿著不同軸向的超導能隙及偽能隙分佈與變化情形。

The existence of pseudo-gap of High Tc Superconductors in over-doped region does not have the last word today. In this thesis, a polarized femtosecond pump-probe spectroscopy system, combined with the technique to grow well-oriented high quality (100) and (001) Y1-xCaxBa2Cu3O7-δ thin films, has been developed to study the anisotropic ultrafast dynamics. Form the measurement of time dependent transient-reflectivity changes, the information of Δ(0)and of over-doped high Tc superconducting thin films have been revealed.