Spin–orbit coupling
Motion in an electric field can couple to spin.
$$H_{\rm R}=\alpha(\sigma_x k_y-\sigma_y k_x)$$
Physical intuition
Motion in an electric field can couple to spin.
Deep dive: physical mechanism
Structural inversion asymmetry produces Rashba coupling; bulk inversion asymmetry can yield Dresselhaus terms.
What is measured experimentally?
Electric-dipole spin resonance and anisotropic relaxation probe coupling.
Assumptions, noise and limitations
The displayed Rashba form assumes a simple two-dimensional model.
Research and simulation exercise
Simulate spin splitting versus momentum.
Connect the ideas
Explore the chapter overview, learning path, and references.