We revisit the spin-injected field effect transistor (spin-FET) by simulating
a lattice model based on recursive lattice Green's function approach. In the
one-dimensional case and coherent regime, the simulated results reveal
noticeable differences from the celebrated Datta-Das model, which motivate thus
an improved treatment and lead to analytic and generalized result. The
simulation also allows us to address inelastic scattering (using B\"uttiker's
fictitious reservoir approach) and lateral confinement effects on the control
of spins which are important issues in the spin-FET device.Comment: 9 pages, 4 figure
