Spin–flip relaxation in a two-electron quantum dot with spin–phonon coupling

We study the spin–flip process from the first excited state to the ground state due to the spin–phonon coupling in a two-electron quantum dot in the presence of a magnetic field. We give several possible relaxation channels before and after the crossing of the Zeeman sublevels. Our results show that the Coulomb interactions between the electrons of different channels play quite different roles and thus inducing different spin relaxation behaviors.

► Spin relaxation channels due to direct spin-phonon coupling are illustrated for two electrons in a quantum dot
► The spin relaxation rate decreases or increases with the magnetic field in different strength regime
► The Coulomb interactions between two electrons play different roles for these relaxation processes.