Simultaneous generation of shift and injection currents in (110)-grown GaAs/AlGaAs quantum wells
Simultaneous generation of shift and injection currents in (110)-grown GaAs/AlGaAs quantum wells
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DOI：
10.1063/1.2360380
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发表时间：
2006-10-15
影响因子：
3.2
通讯作者：
Siegner, U.
中科院分区：
文献类型：
--
作者：
Bieler, M.;Pierz, K.;Siegner, U.
我们已经产生了移位和注入电流在无应变，未掺杂的（110）生长的GaAs/Al 0.3Ga 0.7As量子威尔斯与一个单一的光脉冲，并检测到他们通过自由空间太赫兹实验。通过适当地选择激励脉冲的极化状态，可以沿着沿着某些晶体方向单独产生两个电流，或者沿着沿着相同的晶体方向同时产生它们。注入电流和移位电流的比较使我们能够估计注入电流的强度。在激发能量为1.53eV时，注入电流张量元近似为i2 × 10 ~（7）A/（V ~（-2）s）。这对应于平均速度约为10 km/s的电子注入。此外，在相同的实验条件下的位移和注入电流的强度依赖性的比较表明更强的饱和的位移电流。
We have generated shift and injection currents in unstrained, undoped (110)-grown GaAs/Al0.3Ga0.7As quantum wells with a single optical pulse and detected them via free-space terahertz experiments. By properly choosing the polarization state of the excitation pulse, it is possible to generate both currents alone along certain crystal directions or to simultaneously generate them along the same crystal direction. A comparison of injection and shift currents allows us to estimate the strength of the injection current. At an excitation energy of 1.53 eV the injection current tensor element is approximate to i2x10(7) A/(V-2 s). This corresponds to an injection of electrons with an average velocity of approximate to 10 km/s. Moreover, a comparison of the intensity dependence of shift and injection currents under identical experimental conditions demonstrates a stronger saturation of the shift current.