All-optical injection and control of spin and electrical currents in quantum wells
All-optical injection and control of spin and electrical currents in quantum wells
复制标题
量子阱中自旋和电流的全光注入和控制
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
J. Sipe
中科院分区：
文献类型：
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作者：
A. Najmaie;R. Bhat;J. Sipe
我们表明，单光子和双光子吸收之间的量子干涉可以用来注入自旋电流，有或没有伴随的电流，在无偏置的半导体量子阱结构。其中的电流和自旋电流注入的方向可以相干控制，与作为控制参数的光场的相对相位参数。我们描述了电流的无应变量子阱和量子阱双轴压缩应变下使用Luttinger-Kohn模型，我们工作出特定的例子。如果使用压缩应变来适当地重新排列子带，则可以实现并保持甚至远高于带隙的光子能量的自旋电流的自旋极化程度高于体GaAs中可能的自旋电流的自旋极化程度。
We show that quantum interference between one- and two-photon absorption can be used to inject spin currents, with or without an accompanying electrical current, in unbiased semiconductor quantum well structures. The directions in which the electrical and spin currents are injected can be coherently controlled, with a relative phase parameter of the optical fields as the control parameter. We characterize the currents for an unstrained quantum well and a quantum well under biaxial compressive strain using the Luttinger-Kohn model; we work out particular examples. If compressive strain is used to appropriately rearrange the subbands, then a degree of spin polarization of the spin currents higher than possible in bulk GaAs can be achieved and maintained even for photon energies well above the band gap.