NewArtY/spin-holonomy-plane-wave: Code and data for the paper "Net electron spin rotation in a plane-wave pulse: Holonomy set by the anomalous magnetic moment"

This package contains the code and the numerical data behind the paper

"Net electron spin rotation in a plane-wave pulse: Holonomy set by the anomalous magnetic moment" N. S. Akintsov, A. P. Nevecheria, S. N. Andreev, Qing-Hua Qin.

The paper shows that the net rotation of the spin of an electron crossing a plane-wave pulse of finite duration is a holonomy: it equals -(1/2) a_e^2 A, where a_e = (g-2)/2 is the anomalous magnetic moment and A is twice the signed area swept by the vector potential in the polarization plane. The rotation vanishes identically for linear polarization at any g, and it does not depend on the electron energy, the carrier frequency, the pulse duration, the chirp or the carrier-envelope phase. Finite focusing breaks the law at second order in the diffraction parameter eps = 1/(k w0).

CONTENTS spin_magnitude.py: Plane-wave calculations: the g = 2 null test, the area law, scaling with energy and pulse parameters, the integrator-tolerance scan, and the longitudinal spin projection. holonomy_scan.py: Scan over pulse shapes, chirps, ellipticities and polarization gating that produces the collapse of Fig. 1, plus the angle-wrapping demonstration. focused_beam.py: Lax-Louisell-McKnight focused-beam fields, Maxwell residuals, and the eps^2 violation of the area law. indep_check*.py: Four independent re-derivations of the generator and of the area law. make_fig*.py: Figure generation. plotstyle.audit() walks the finished. plotstyle.py: figure and fails before a file is written if any font or line falls below the APS minimum. reproduce_all.py: Single entry point; regenerates every number and every figure quoted in the paper. *.json, *.log: The results themselves. Every number quoted in the paper and in its supplemental material comes from these files. figproofs/: Raster proofs of the four figures. legacy/: Superseded scripts from an earlier stage of the project, kept for provenance. No result in the paper depends on them.