Release Notes#

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For more information, see the Releases on GitHub.

Version 1.3.0#

2026-05-04

Minor release intoducing an overhaul of the bls module, especially the addition of the reciprocity theorem approach for calculating the BLS signal.

What’s new#

  • bls module now includes functions for calculating the BLS signal using the reciprocity theorem, which is less computationally demanding than the Green function approach. New example notebooks Modeling BLS signal from a single magnetic layer using the reciprocity theorem #1 and Modeling BLS signal from a single magnetic layer using the reciprocity theorem #2 were prepared for demonstration of the new functions.

  • bls.getBLSsignal() is marked as deprecated and will be removed in SWT 1.5.0, since it does not comply with the new API of the BLS module. A replacement for this function was added as bls.get_signal_GF_focal(), which is the same function but with a new name and a slightly changed API (see the docstring for details); it is also flagged as experimental for now, since we want to improve its implementation and performance, and clarify the API before making it a standard part of the module. Calling the old function is still possible, but doing so will raise a deprecation warning.

  • bls module now includes a sub-module bls.susceptibilities with functions for calculating the magneto-optical electric susceptibility tensors, which are used in the BLS signal calculations. Linear and quadratic magneto-optical effects are supported and can be used also for static magneto-optical characterization. The quadratic ones also offer linearization in simple geometries (advantageous for dynamic magnetization with small precession amplitudes, typically for BLS calculations).

  • A better description of the bls module was prepared in the documentation.

  • bls.ObjectiveLens class now includes a method getPupilField() for calculating the electric field distribution directly in the reciprocal space.

  • Added a rotate_field() function for rotating a vectorial field distribution (e.g. the electric polarization) in the 2D plane of the sample, i.e. around z axis. This is useful, e.g., for calculating the BLS signal for different in-plane orientations of the sample without the need to recalculate the dispersion relation and Bloch functions for each orientation.

Fixes#

  • Docstring fixes and minor improvements.

  • Documentation improvements.

  • Instructions in CONTRIBUTING.md updated.

Version 1.2.1#

2026-02-23

Patch featuring important dispersion-model fixes and small tweaks.

What’s new#

  • All GetBlochFunction() methods now include optional weighting by Bose-Einstein distribution.

  • New physical constant - Planck constant H - added to the module.

Fixes#

  • Anisotropy tensor in SingleLayer is now correctly handled for dispersion relation calculations.

  • Correct formula for ellipticity use in SingleLayer.

  • Docstring fixes and minor improvements, mainly in DoubleLayerNumeric.

  • BLS example now includes also first PSSW mode and usage of BE distribution (see _example_nbs/BLS_signal_from_single_layer).

  • Documentation improvements.

  • Instructions in CONTRIBUTING.md updated.

Version 1.2.0#

2025-11-12

Dispersion model fixes and static magnetization problem solver.

What’s new#

  • All BLS-related functions moved to a separate submodule bls. It will be extended in future releases.

  • bls.getBLSsignal() now returns also the polarization induced in the ferromagnetic film.

  • Added static magnetization solver MacrospinEquilibrium for finding the equilibrium orientation of the magnetization in a ferromagnetic film under an applied magnetic field and uniaxial anisotropies. This can be used to find the angle of magnetization before calculating the spin-wave dispersion. For this, helper functions sphr2cart() and cart2sphr() were added as well as an example notebook (see Static magnetization equilibrium and hysteresis loops).

  • Added a dependency on the (lightweight) tqdm package for progress bars.

  • Class SingleLayer now supports dispersion calculation with the static magnetization at an arbitrary angle to the film plane and with any uniaxial anisotropy.

Fixes#

  • Instructions in CONTRIBUTING.md updated.

  • SingleLayerNumeric now notifies the user if the used geometry is valid, referring to the partially-out-of-plane magnetization, which is not currently supported. (We hope to fix this in future releases.)

  • Docstring fixes and minor improvements.

  • Documentation improvements.

Version 1.1.1#

2025-08-26

A small patch mostly related to documentation.

Fixes#

  • Docstring fixes and documentation improvements.

Version 1.1.0#

2025-08-21

Improving the module!

What’s new#

  • Added functions for basic Brillouin light scattering (BLS) intensity calculations.

  • Added method GetBlochFunction to all dispersion models. This is used in the BLS modelling functions. Can be used also for PSWS spectra (planned).

  • Added dispersion model for a single film coupled to a superconducting layer (SingleLayerSCcoupled), only for DE spin waves for now.

  • Added dispersion model for magnon-polaritons in bulk ferromagnets (BulkPolariton).

  • Added documentation.

  • Release to PyPI.

  • Class SingleLayerNumeric extended from 3 to an arbitrary number of modes.

Fixes#

  • Fixed a bug in SingleLayerNumeric that caused incorrect results for nonzero KuOOP.

  • Removed irrelevant parameter nc from SingleLayer in zeroth perturbation methods.

  • Update of parametric pumping methods within SingleLayer.

  • Docstring fixes and minor improvements.

Version 1.0.0#

2025-03-09

The first release of a reworked SWT. Fully functional with a hopefully stable syntax.