Giant Spin Relaxation Anisotropy in Zinc-Blende Heterostructures

Spin relaxation in-plane anisotropy is predicted for heterostructures based on zinc-blende semiconductors. It is shown that it manifests itself especially brightly if the two spin relaxation mechanisms (Dyakonov-Perel and Rashba) are comparable in efficiency. It is demonstrated that for the quantum well grown along the [001] direction, the main axes of spin relaxation rate tensor are [110] and $[11\ifmmode\bar\else\textasciimacron\fi{}0].$