SpinCirc

Status: frozen Category: research Owner: alawein Visibility: private Purpose: Spintronics circuit simulation and modeling research workspace. Next action: continue

Public value

SpinCirc is a research-portfolio candidate if it documents the spintronic circuit model, expected inputs, validation examples, and relation to published work. Public polish should focus on reproducibility and scientific context rather than treating the repo as a generic code library.

Publication boundaries

• Tie examples and figures to regeneration commands where possible.
• Confirm license, citation expectations, and data provenance before public promotion.
• Keep unpublished paper drafts, private benchmark data, and machine-local outputs out of public examples.
• Mark exploratory notebooks or historical experiments as non-canonical.

About

Computational framework for spintronic device modeling using equivalent-circuit spin-transport methods. Based on Alawein & Fariborzi, IEEE J-XCDC 2018.

Features

• Spin Transport -- Drift-diffusion solver with 4x4 conductance matrix
• Magnetization Dynamics -- LLG/LLGS integration with thermal noise
• Device Models -- MTJs, spin valves, all-spin logic, multiferroic devices
• Circuit Integration -- EDA-compatible compact models
• Material Database -- Properties for common spintronic materials

Implementation

• MATLAB Core -- Numerical solvers for coupled transport-magnetodynamics
• Python Tools -- Data analysis and ML integration
• Verilog-A Models -- Compact models for circuit simulation
• Validation -- Benchmarks against published experiments

Device Models

• Magnetic Tunnel Junctions (MTJs) -- TMR calculation, bias dependence, switching
• Nonlocal Spin Valves -- Hanle precession measurements, temperature effects
• All-Spin Logic (ASL) -- Logic gates with process variation analysis
• Multiferroic Devices -- Voltage-controlled magnetic anisotropy

Installation

MATLAB

Requires R2024b+ with Signal Processing and Optimization toolboxes.

addpath(genpath('matlab'));

Python

python -m venv spincirc-env
source spincirc-env/bin/activate
pip install -r python/requirements.txt
pip install -e .

Verilog-A Models

Copy .va files to your simulator's model directory:

cp verilogA/models/*.va $SPECTRE_HOME/tools/spectre/etc/ahdl/

Usage

% Nonlocal spin valve simulation
device = NonlocalSpinValve();
device.setGeometry(2e-6, 100e-9, 10e-9);
device.setMaterials('NiFe', 'Cu');

% Hanle measurement at 100 uA
field_range = linspace(-50e-3, 50e-3, 101);
results = device.measureHanle(100e-6, field_range);
device.plotResults('save_figures', true);

Project Structure

spincirc/
├── matlab/          # MATLAB core (transport/LLG solvers, device models, tests)
├── python/          # Analysis tools (data processing, ML, visualization)
├── verilogA/        # SPICE compact models and test circuits
├── examples/        # Demo scripts
└── docs/            # Documentation

Testing

runtests('matlab/tests');

pytest python/tests/ -v --cov=python

Citation

@article{alawein2018circuit,
  title={Circuit Models for Spintronic Devices Subject to Electric and Magnetic Fields},
  author={Alawein, Meshal and Fariborzi, Hoseein},
  journal={IEEE Journal on Exploratory Solid-State Computational Devices and Circuits},
  volume={4},
  number={2},
  pages={76--85},
  year={2018},
  publisher={IEEE},
  doi={10.1109/JXCDC.2018.2876456}
}

License

MIT License -- see LICENSE.

Ownership

• Maintainer: @alawein
• Support: GitHub Issues