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超短激光技术的发展为研究材料中的超快光动方学过程提供了重要的实验手段,也使得人们能够更为深入地研究电子的自旋动力学行为.GaAs(100)表面由于费米钉扎而会导致能带弯曲,位于该区域的电子及其自旋特性将会明显不同于体相材料中的情况.利用时间分辨和自旋分辨的双光子光电子发射技术研究了p型掺杂GaAs(100)表面的电子极化动力学过程.结果表明,由费米钉扎而引起的能带弯曲明显影响电子的自旋弛豫过程,从实验上观察到了GaAs(100)表面能带弯曲区域的电子自旋翻转时间存在近2个量级的差异(从几纳秒到几十皮秒),基于电子_自旋交换相互作用的BAP机理在自旋弛豫过程中起着主导作用.
The development of ultrashort laser technology provides an important experimental method for studying the ultrafast phototachography process in materials and also allows one to study the spin behavior of electrons in more depth. The surface of GaAs (100) Pins will lead to band bending, located in the region of the electron and its spin characteristics will be significantly different from the bulk phase material using the time-resolved and spin-resolved two-photon photoelectron emission technology p-type doping The electron polarization kinetics of GaAs (100) surface was investigated. The results show that the band bending caused by Fermi pinning significantly affects the electron spin-relaxation process. The energy band bending of GaAs (100) There are nearly two orders of magnitude difference (from a few nanoseconds to tens of picoseconds) of electronic spin flip time in the region. The BAP mechanism based on the electron-spin exchange interaction plays a leading role in the spin relaxation process.