Dephasing mechanisms of Bloch oscillations in GaAs/Al0.3Ga0.7As superlattices investigated by time-resolved terahertz spectroscopy
Dephasing mechanisms of Bloch oscillations in GaAs/Al0.3Ga0.7As superlattices investigated by time-resolved terahertz spectroscopy
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DOI：
10.1063/1.1633013
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发表时间：
2003-12
影响因子：
4
通讯作者：
N. Sekine;Y. Shimada;K. Hirakawa
中科院分区：
文献类型：
--
作者：
N. Sekine;Y. Shimada;K. Hirakawa
利用时间分辨太赫兹光谱系统研究了GaAs/Al 0. 3Ga 0. 7As超晶格中布洛赫振荡（BO）的弛豫时间随偏置电场、温度和结构参数的变化.结果表明，当偏置场超过1.9kV/cm时，弛豫时间显著增加约80%，并出现明显的Wannier-Stark阶梯. BOs的主要退相机制被确定为低于（高于）临界偏置电场的界面粗糙散射（合金无序散射）。从温度依赖性，它也被发现，声子散射中起着相当小的作用，在退相过程。
We systematically investigated the relaxation time of Bloch oscillations (BOs) in GaAs/Al0.3Ga0.7As superlattices as functions of the bias electric field, temperature, and structural parameters using the time-resolved terahertz spectroscopy. It was found that the relaxation time dramatically increases by ∼80% and a clear Wannier–Stark ladder shows up when the bias field exceeds ∼9 kV/cm. The dominant dephasing mechanism of BOs was identified to be interface roughness scattering (alloy disorder scattering) below (above) the critical bias electric field. From the temperature dependence, it was also found that phonon scattering plays a rather minor role in the dephasing process.