  Weak antilocalization (WAL) effect due to the interference corrections to the
conductivity has been studied experimentally in a strained InGaAs/InP quantum
well structure. From measurements in tilted magnetic filed, it was shown that
both weak localization and WAL features depend only on the normal component of
the magnetic field for tilt angles less than 84 degrees. Weak antilocalization
effect showed non-monotonous dependence on the gate voltage which could not be
explained by either Rashba or Dresselhouse mechanisms of the spin-orbit
coupling. To describe magnetic field dependence of the conductivity, it was
necessary to assume that spin-orbit scattering time depends on the external
magnetic field which quenches the spin precession around effective, spin-orbit
related, magnetic fields.
