以飛秒光譜研究六方晶系結構鈥錳氧之超快動力學

Abstract

在此論文中，使用標準激發-探測實驗系統以及時間解析磁光柯爾效應實驗系統，以不同偏振態(左旋光、右旋光、線偏振光)的激發光，在不同溫度、不同磁場的環境下研究六方晶系鈥錳氧(001)的超快動力學。藉由電子的d-d激發過程探究樣品中磁矩的失序程度、失序時間、回復時間。另外，透過量測線偏振探測光的柯爾效應，研究在不同外加磁場及不同偏振態的光激發下，樣品的光致雙折射效應與磁結構之關係。

We studied the ultrafast dynamics in hexagonal HoMnO3 by pump-probe system and time-resolved MOKE system with different polarization pump beam (linear, left circular, right circular polarization), various temperatures, and magnetic field. The disorder, disorder time, and reorder time of magnetic moment in hexagonal HoMnO3 have been observed via the d-d excitation of electrons. Moreover, by measuring the Kerr signal in time-resolved MOKE system, the relation between photon induced birefringence and magnetic structure has been systematically studied in different temperatures, external magnetic field, and different polarization pump beam.