Abstract:

Inevitable disorder in spin-orbit coupling is an important feature of real low-dimensional electron structures. Here the spin-orbit disorder plays an important or the crucial role: (i) Si/Ge quantum wells, (ii) spin helix patterns, (iii) GaAs (011) quantum wells, and (iv) graphene.
We study theoretically two main manifestations of the spin-orbit disorder. First one is the spin relaxation, which can occur even without momentum relaxation. We show that in a high-mobility electron gas subject to a magnetic field the spin-orbit randomness leads to a spin memory effect and to a fast Gaussian rather than a simple exponential spin relaxation.
The other manifestation is the abilities of spin manipulation. Due to the disorder in spin-orbit coupling, a time-dependent external electric field generates a spatially random spin-dependent perturbation. Even for a very weak disorder, at typical experimental conditions the efficiency of the induced electric dipole spin resonance can be very high. In addition, spin-flip transitions lead to considerable corrections to the Drude conductivity, which can be observed experimentally. These effects can be important for possible applications in spintronics.
 
 
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