半导体量子阱中电子自旋弛豫和动量弛豫  

Electron spin relaxation and momentum relaxation in semiconductor quantum wells

作　　者：吴羽[1] 焦中兴[1] 雷亮[1] 文锦辉[1] 赖天树[1] 林位株[1] 

机构地区：[1]中山大学光电材料与技术国家重点实验室,物理系广州510275

出　　处：《物理学报》2006年第6期2961-2965,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10274107;60178020;60378006);国家自然科学基金重大项目(批准号:60490290);广东省自然科学基金项目(批准号:04009736)资助的课题~~

摘　　要：根据电子自旋轨道耦合对自旋极化弛豫影响的DP机理进一步导出了半导体中电子自旋弛豫与动量弛豫及载流子浓度的关系,并采用飞秒抽运探测技术在室温下测量AlGaAs/GaAs多量子阱中载流子浓度在1×1017—1×1018cm-3范围内,电子自旋弛豫时间由58ps增加至82ps的变化情况,与理论计算值符合,说明了随着载流子浓度的增加,载流子间的频繁散射加速了电子动量驰豫,减弱了电子自旋轨道耦合作用,从而延长了电子自旋寿命.The dependence of electron spin relaxation on the momentum relaxation and carrier density are investigated based on the spin-orbit coupling and D＇yakonov-Perel relaxation mechanism. Experimental results obtained by using femtosecond pump-probe technique in AlGaAs/GaAs multiple quantum wells at room temperature show that the spin relaxation time increases from 58 to 82ps with the carrier density increases from 1 × 10^17 to 1× 10^18cm^-3, consistent with the theoretical prediction. This results reveals that with the increase of the carrier density, the spin-orbit interaction reduces due to more frequent momentum scattering, sothat the spin relaxation time prolongs.

关 键 词：电子自旋轨道耦合 电子自旋弛豫和动量弛豫 飞秒光谱技术 

分 类 号：O471.1[理学—半导体物理] O413.1[理学—物理]