  Spin-based logic devices could operate at very high speed with very low
energy consumption and hold significant promise for quantum information
processing and metrology. Here, an in-house developed, experimentally verified,
ensemble self-consistent Monte Carlo device simulator with a Bloch equation
model using a spin-orbit interaction Hamiltonian accounting for Dresselhaus and
Rashba couplings is developed and applied to a spin field effect transistor
(spinFET) operating under externally applied voltages on a gate and a drain. In
particular, we simulate electron spin transport in a \SI{25}{nm} gate length
\chem{In_{0.7}Ga_{0.3}As} metal-oxide-semiconductor field-effect transistor
(MOSFET) with a CMOS compatible architecture. We observe non-uniform decay of
the net magnetization between the source and gate and a magnetization recovery
effect due to spin refocusing induced by a high electric field between the gate
and drain. We demonstrate coherent control of the polarization vector of the
drain current via the source-drain and gate voltages, and show that the
magnetization of the drain current is strain-sensitive and can be increased
twofold by strain induced into the channel.
