Phonon-assisted mechanism for quantum nuclear-spin relaxation

The phonon-assisted mechanism for relaxing the polarized nuclear spins in the clean limit of a two-dimensional electron-gas (2DEG) system is studied under the quantum-Hall-effect condition. This mechanism consists of two processes. In the first process, electron and nuclear spins are simultaneously reversed by the hyperfine interaction. In the second process, on the other hand, only electron spins are reversed by their coupling to the lattice strain. The quantum nuclear-spin relaxation rate (${\mathit{T}}_1^{\mathrm{-}1}$) is computed as functions of magnetic field and temperature. A possibility that ${\mathit{T}}_1^{\mathrm{-}1}$ can be used as a magnetic probe in studying the electron-electron interaction in high-mobility 2DEG systems is discussed.