  The electron spin dynamics in (111)-oriented GaAs/AlGaAs quantum wells is
studied by timeresolved photoluminescence spectroscopy. By applying an external
field of 50 kV/cm a two-order of magnitude increase of the spin relaxation time
can be observed reaching values larger than 30 ns; this is a consequence of the
electric field tuning of the spin-orbit conduction band splitting which can
almost vanish when the Rashba term compensates exactly the Dresselhaus one. The
measurements under transverse magnetic field demonstrate that the electron spin
relaxation time for the three space directions can be tuned simultaneously with
the applied electric field.
