Datta-Das Spin Transistor (2D): Rashba Precession & Switching Curve

This is the 2D counterpart of the Datta–Das spin field-effect transistor simulator: the same Rashba spin-orbit Hamiltonian and the same precession angle θ(x) = 2m*αx/ħ², but rendered as flat, literally computed plots instead of a 3D scene. A channel strip shows electrons flowing from source to drain with their instantaneous spin direction drawn as an arrow; a sinusoid chart plots the spin's Sy and Sz components as genuine cosine and sine curves across the channel so you can read the precession phase directly off the curve; and a third chart sweeps the gate-tunable Rashba coefficient α and re-solves the drain current at every value, tracing out the full oscillatory on/off switching curve that is the defining signature of the real device. Tune the Rashba coefficient, channel length or effective mass and watch all three views update together from the same underlying physics.