lemurpwned / pymag

GUI and engine for magnetic simulations

Welcome to PyMag documentation

This is a frontend GUI for some of the cmtj functionalities. It's possible that you will be able to simulate most of your experiments here if you use:

• SD-FMR
• Harmonic Hall voltage
• PIMM

techniques for your expeirments.

Requirements

• Python 3.8 or higher
• PyQt6 (pip install pyqt6) -- installing PyMag should automatically install PyQt6 as well
• cmtj -- installing PyMag should automatically install cmtj as well

---

Recommended installation of PyQT6

Mac OS

brew install pyqt6

or

brew install pyqt@6

For M1/M2 architecures it sometimes works better to install:

python -m pip install pyqt6

Linux/Ubuntu

sudo apt install python3-pyqt6

and it sometimes requires additional manual installation (or some combination of the below):

sudo apt install pkg-config libgl1-mesa-dev libxcb*-dev libfontconfig1-dev libxkbcommon-x11-dev libgtk-3-dev

Quickstart

For quick installation you only need to install the package first:

It is highly recommended to install PyMag inside a python environment

• From Github repository

git clone https://github.com/LemurPwned/PyMag
cd PyMag
python3 -m pip venv .pymag 
source .pymag/bin/activate
pip3 install --upgrade pip
pip3 install .

Example

You can find a sample simulation description in docs/example.md.

Running

You can launch anywhere with a simple command

python3 -m pymag run

It's possible to alias that for a quicker run:

alias pymag "python3 -m pymag run"

For persistence add this to your .bashrc if you're on Linux. On Windows you may simply create a shortcut.

---

Parameters

Here's an explanation of the parameters in the table:

Parameter	Meaning
$\mu_0 M_\mathrm{s}$	Magnetisation saturation
$J_1$	IEC value
$J_2$	IEC value (quadratic term)
$K_{u}$	Anisotropy value
$\mathbf{K}_{dir}$	Anisotropy axis
$\alpha_\mathrm{G}$	Gilbert damping parameter
$\mathbf{N}_\mathrm{demag}$	diagonal of demagnetisation tensor
$t_\mathrm{FM}$	thickness of a FM layer
$w$	width of a sample
$l$	length of the sample
$H_\mathrm{DL}$	magnitude of the damping-like torque
$H_\mathrm{FL}$	magnitude of the field-like torque
$H_\mathrm{Oe}$	magnitude of the Oersted field in 1/m
$\mathbf{p}$	polarisation vector

The Oersted field value is multiplied by the current value in the code, hence the unit is 1/m (1/m * A = A/m).

Resistance

For the interpretation of the remaining resistance, please refer to the supplementary material of the paper Kim et al. (2016), Spin Hall Magnetoresistance in Metallic Bilayers, Phys. Rev. Let. 116, 9, 097201:

• $R_\mathrm{XX0}$
• $R_\mathrm{XY0}$
• $R_\mathrm{AMR}$
• $R_\mathrm{SMR}$
• $R_\mathrm{AHE}$

pymag's Issues

Export to csv bugs

The simulation name is not added to the filename of exported csv.

Unit labels

Please add unit labels in the GUI.

GUI bugs

When selecting multiple layers in the gui that want to be deleted, only the last selected layer was deleted.