Spin-flip transitions between Zeeman sublevels in semiconductor quantum   dots
  We have studied spin-flip transitions between Zeeman sublevels in GaAs electron quantum dots. Several different mechanisms which originate from spin-orbit coupling are shown to be responsible for such processes.   It is shown that spin-lattice relaxation for the electron localized in a quantum dot is much less effective than for the free electron. The spin-flip rates due to several other mechanisms not related to the spin-orbit interaction are also estimated. 
Alexander V. Khaetskii and Yuli V. Nazarov