Release Notes#

Version 1.3.1#

2023-06-12

Hotfixes#

  • fixed installation problem on Windows related to compilation

  • fixed problem related to multiprocessing on Windows

  • fixed error on calculating absorption when some frequencies are NaN (now it properly skips these modes)

Other#

  • included description in documentation on how to use TetraX in standalone python scripts.

Version 1.3.0#

2023-05-23

tl;dr#

  • inhomogeneous material parameters

  • extract data along curves

  • new sample visualization

  • added calculation of mode linewidths

  • 5 new examples

  • 3D confined samples and antiferromagnets (experimental)

  • other

New features#

  • TetraX now supports inhomogeneous material parameters, namely variations in exchange stiffess constant \(A_\mathrm{ex}\) and saturation magnetization \(M_\mathrm{s}\). Both attributes can now supplied to a sample as scalar arrays. For example, to set a linearly varying saturation magnetization, the following code snippet can be used.

    Mavrg = 800e6
dMdx = 10e6

sample.Msat = Mavrg + dMdx * sample.xyz.x

    The current average magnetization is now obtained with sample.Msat_avrg. For more details, see Examples Double layers of Py / CoFeB and Magnetization-graded waveguides.

  • The effective-field terms that correspond to the current magnetization state of a sample can now be accessed with

    • sample.Bexc (exchange field)

    • sample.Bdip (dipolar field)

    • sample.Buni (uniaxial-anistropy field)

    • sample.Bcub (cubic-anistropy field)

    • sample.Bdmi (bulk DMI field)

    • sample.Bidmi (interfacial-DMI field)

    All fields are return as MeshVector fields in units of Tesla.

  • One can now extract data along a curve of scalar or vector fields on a mesh. This can be done using sample.scan_along_curve() which accepts curves specified either by their start end and end points (will result in a straight line) or by supplying all interpolation points along the curve (enables arbitrary curves). This method calls the new helper function tx.helpers.math.interpolate_along_curve(). For a demonstration, see Example Linescan example on the magnetization-graded waveguides.

  • The linewidths of spin-wave modes can now be calculated separately from the absorption() experiment. For this one can use the new linewidths() experiment or, alternatively, set linewidths=True when calculating the dispersion.

    exp.eigenmodes()
linewidths = exp.linewidths()

# Or shorter
linewidths = exp.eigenmodes(..., linewidths=True)

    Here the new linewidths data frame is the familiar dispersion table extended by the linedwidth columns (“Gamma0/2pi (GHz)” and so on). An application is found in the new example Thick film dispersion and linewidth analysis.

New Examples#

Minor Changes#

  • The visualization of waveguides and multilayers has been changed to include an additional mesh that hints at the full three-dimensional shape. For this, both sample.show() and ExperimentalSetup.show() now include the option show_extrusion which is True by default. Furthermore, the grid is now hidden by default which, in both, cases, can be adjusted with the show_grid option.

  • Apart from using tetrax.sample_average() one can also now use the more convenient sample.average() which only accepts the vector/scalar field as an argument and does not require to pass the sample object itself.

Other#

  • Updated User Guide with new features.

  • Updated Publications.

  • Internal restructuring of magnetic tensors to allow for more unified implementation with antiferromagnets.

  • Magnetic tensors are equipped with an update method that handles changes in material parameters but avoids unneccessary recalations.

  • We now support antiferromagnets as an experimental set of features including

    • all interactions except dipole-dipole

    • additionally, we support non-uniform DMI

    • visualiziation of AFM mode profiles

    Use on your own risk (and tell us your experiences).

  • 3D confined samples are now supported for FMs (without dipolar interaction) and for AFMs, both as an experimental feature.

Bug fixes#

  • Fixed a bug that gave an error when relaxation with least-square method failed.

  • Error related to numpy datatype and scipy sparse matrices fixed.

Version 1.2.0#

2022-07-15

New features#

  • TetraX now supports layer samples, which can be created with tetrax.create_sample(geometry="layer") and are represented by 1D line-trace mesh along the normal direction of the layer(s). For this, the plane-wave Fredkin-Koehler method has been expanded to infinitely-extended layers (preprint available at arXiv, submitted to AIP Advances). See Example: Thick film dispersion and perturbation analysis.

  • Templates for layer samples were added, in form of mono, bi and multilayers as possible 1D geometries in the tetrax.geometries submodule:

  • Bilinear interlayer-exchange interaction is now available (only for layered systems), see Example Exchange-coupled bilayers (SAF). The interlayer-exchange constant sample.J1 (in J/m2) can also have different values between different layers in a multilayered sample, by supplying a list of values (see User Guide).

  • The eigenmode calculation ExperimentalSetup.eigenmodes(k=k_list,...) now accepts lists or 1D arrays as a parameter for k, e.g. to specify a non-equidistant wave-vector range.

  • Cubic anistropy (first order) is now properly implemented and can be used for both waveguides and layer samples. See Example: Cubic anisotropy.

  • Rudimentary mode-profile visualization and animation has been added. If available, a mode profile can be visualized using ExperimentalSetup.show_mode(k=...,N=...). See User Guide for details and Example: Mode movie.

  • The numerical experiments implemented in TetraX are often based on seminal papers. In order to give credit to these works, when conducting a numerical experiment, TetraX now saves references important for this experiment to a bibtex file called references.bib, found in the sample directory. In this file, each entry contains a comment field describing how the reference was important for the computation. When publishing results calculated with TetraX in your research, please also give credit to the works which are important for the numerical experiments you conducted.

Minor changes#

  • When modes at a specific wave vector cannot be calculated, now, NaNs are inserted into the dispersion dataframe. Previously, this simply caused an error.

  • Warning message for magnetization pointing into the z direction removed.

  • Additional geometry added for waveguides, round_wire_cross_section_refined() which supports local mesh refinement (see documentation).

Bug fixes#

  • ExperimentalSetup.Bext is now initialized as MeshVector filled with zeros. Previously, an error occurred when not specifying any external field.

  • Automatic dispersion saving and perturbate-dispersion analysis have been reimplemented. Somehow they got lost in a previous merge. Saving of dispersions can be controlled with save_disp=True and ExperimentalSetup.eigenmodes(fname="dispersion.csv",...).

  • The director of uniaxial anisotropy e_u can now be specified as a triplet, e.g. [0, 0, 1], just like magnetization or external field. Previously, this caused complications with the possibility to set multiple uniaxial anistropies.

Other#

  • To make upcoming implementation of antiferromagnets easier, spherical mesh vectors for FM and AFM, conversion methods to cartesian and back, and local mesh vectors for AFM have been implemented.

  • Updated documentation.

  • Added instructions for installation on Windows computers.

  • 4 examples included to the package:

Version 1.1.0#

2022-03-31

New features#

  • Added the tetrax.sample_average() function available, which takes the average of a vector or scalar field in a given sample (can be volume, surface or line)

  • verbose={True, False} added to all numerical experiments, allows to silence all output (except warnings)

  • Saving vector/scalar fields to vtk files is now possible using tetrax.write_field_to_file() by

    tetrax.write_field_to_file(field, sample)

    or with the optional keywords

    tetrax.write_field_to_file(field, sample, fname, qname)

    As an alternative, the method AbstractSample.field_to_file() can be used, where the sample parameters is obviously omitted.

  • Added new equilibrium states bloch_wall and neel_wall to tetrax.vectorfields.

  • Added new geometry tube_segment_cross_section for waveguide samples to tetrax.geometries.

  • Plotting of scalar and vector fields on a sample is now possible using the plot() method of a sample object.

  • Pertubation analysis and reverse-engineering of general spin-wave dispersions according to Phys. Rev. B 104, 174414 (2021) is now possible within the eigenmodes() experiment, see User Guide Numerical Experiments.

  • Implemented cubic anistropy (linearized dynamic field not properly tested yet).

Minor changes#

  • relax() experiment now returns only a boolean denoting the relaxation success

  • magnetization is automatically saved into folder of experimental setup after running relax()

  • dispersion is automatically saved to into folder of experimental setup after running eigenmodes()

Other#

  • Populated User Guide and API reference.

  • Added more examples.

  • Indroduced MeshVector, MeshScalar and related data types.

Version 1.0.1#

2022-03-07

Initial release.