  The spin-orbit interaction of two-dimensional (2D) electrons in semiconductor
quantum wells is usually considered to be determined by the band profile of a
heterostructure. In the GaAs/AlGaAs type heterosystems, this interaction
consists of the isotropic Bychkov-Rashba term, which is absent in symmetric
wells, and the anisotropic Dresselhaus term, reflecting the lattice symmetry.
It is well-known that the first term can be controlled by electric fields in
the growth direction: external or internal, induced by a charge density of 2D
electrons. In this work we reveal that the 2D electron charge can substantially
affect also the Dresselhaus interaction in symmetric quantum wells. Within the
one-band electron Hamiltonian containing, together with the bulk Dresselhaus
interaction, the two contributions to the Dresselhaus term from the quantum
well interfaces, we show that the internal electric field from the 2D electron
charge density can substantially renormalize the anisotropic spin-orbit
interaction of 2D electrons. This effect may be important in quantitative
studies of spin-dependent phenomena in quantum wells.
