Spin-phase relaxation of two-dimensional holes localized in a fluctuating potential

We investigate a mechanism of spin phase relaxation for holes localized by an in-plane potential fluctuation in a quantum well. Dephasing is caused by the hole spin precession in a magnetic field with a fluctuation in the transverse g factor linked to the depth and the shape of localizing potential. The mechanism can be recognized by the linear dependences on magnetic field and the quadratic dependence on quantum well width. Quantitative analyses show the importance of this relaxation mechanism for deep fluctuative states of holes.