  The study of electron transport and scattering processes limiting electron
mobility in high-quality semiconductor structures is central to solid-state
electronics. Here, we uncover an unavoidable source of electron scattering
which is caused by fluctuations of nuclear spins. We calculate the momentum
relaxation time of electrons in quantum wells governed by the hyperfine
interaction between electrons and nuclei and show that this time drastically
depends on the spatial correlation of nuclear spins. Moreover, the scattering
processes accompanied by a spin flip are a source of the backscattering of
Dirac fermions at conducting surfaces of topological insulators.
