Bel'kov V V, Olbrich P, Tarasenko S A, Schuh D, Wegscheider W, Korn T, Schüller C, Weiss D, Prettl W, Ganichev S D
Terahertz Center, University of Regensburg, 93040 Regensburg, Germany.
Phys Rev Lett. 2008 May 2;100(17):176806. doi: 10.1103/PhysRevLett.100.176806.
Symmetry and spin dephasing in (110)-grown GaAs quantum wells (QWs) are investigated applying magnetic field induced photogalvanic effect and time-resolved Kerr rotation. We show that magnetic field induced photogalvanic effect provides a tool to probe the symmetry of (110)-grown quantum wells. The photocurrent is only observed for asymmetric structures but vanishes for symmetric QWs. Applying Kerr rotation we prove that in the latter case the spin relaxation time is maximal; therefore, these structures set the upper limit of spin dephasing in GaAs QWs. We also demonstrate that structure inversion asymmetry can be controllably tuned to zero by variation of delta-doping layer positions.
利用磁场诱导光电流效应和时间分辨克尔旋转，研究了在（110）生长的砷化镓量子阱（QW）中的对称性和自旋退相。我们表明，磁场诱导光电流效应提供了一种探测（110）生长量子阱对称性的工具。仅在非对称结构中观察到光电流，而在对称量子阱中光电流消失。应用克尔旋转，我们证明在后一种情况下自旋弛豫时间最大；因此，这些结构设定了砷化镓量子阱中自旋退相的上限。我们还证明，通过改变δ掺杂层位置，可以将结构反演不对称性可控地调至零。
