Crate spintronics 

spintronics

Version 0.3.0 - Advanced physics modules, higher-order integrators, SIMD optimization

A pure Rust library for simulating spin dynamics, spin current generation, and conversion phenomena in magnetic materials and topological materials.

Copyright (c) 2025 COOLJAPAN OÜ (Team KitaSan)

Licensed under MIT OR Apache-2.0

Overview

This library implements physical models established by Prof. Eiji Saitoh’s research group (Univ. Tokyo/RIKEN) and the broader spintronics community:

Core Physics Effects

• Spin Pumping: Generation of spin current from magnetization precession
• Inverse Spin Hall Effect (ISHE): Conversion of spin current to charge current
• Spin Seebeck Effect (SSE): Thermal generation of spin current
• Spin-Orbit Torque (SOT): Current-driven magnetization switching
• Dzyaloshinskii-Moriya Interaction (DMI): Skyrmion stabilization
• Topological Hall Effect: Berry phase from skyrmion textures
• Rashba Effect: 2DEG spin splitting and spin-momentum locking
• Edelstein Effect: Spin-to-charge conversion in non-centrosymmetric systems
• Spin Nernst Effect: Thermal gradient → transverse spin current

Key Features

• ✅ 718 tests passing (718 library tests, v0.3.0)
• ✅ Advanced integrators - Dormand-Prince RK5(4)/RK8(7), symplectic methods (v0.3.0)
• ✅ New physics modules - Altermagnets, Orbitronics, Frustrated magnets, Hopfions, Magnon BEC, Magnetoelastics (v0.3.0)
• ✅ 25 examples organized by difficulty (v0.3.0)
• ✅ Interactive web demo - Axum + HTMX subcrate with 4 physics simulations (v0.2.0)
• ✅ 5 experimental validations against landmark papers
• ✅ WebAssembly support for browser-based simulations
• ✅ FEM solver with advanced iterative methods
• ✅ Performance optimized - 21 inline attributes on hot-path functions (v0.2.0)
• ✅ Memory optimized - Pool allocator reduces allocations by 99% (v0.2.0)
• ✅ Python bindings via PyO3 (v0.2.0)
• ✅ Serde serialization for data interchange (v0.2.0)
• ✅ HDF5 export for large datasets (v0.2.0)
• ✅ Unit validation - 14 validators for physical quantities (v0.2.0)
• ✅ Zero warnings - production-quality code

Key References

• E. Saitoh et al., “Conversion of spin current into charge current at room temperature: Inverse spin-Hall effect”, Appl. Phys. Lett. 88, 182509 (2006)
• K. Uchida et al., “Observation of the spin Seebeck effect”, Nature 455, 778-781 (2008)
• I. M. Miron et al., “Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection”, Nature 476, 189 (2011)
• S. Woo et al., “Observation of room-temperature magnetic skyrmions”, Nat. Mater. 15, 501 (2016)

Architecture

The library is organized into ~28 physics-focused modules:

Core Infrastructure

• constants: Physical constants (ℏ, γ, e, μ_B, k_B, 20+ NIST-validated values)
• vector3: Optimized 3D vector operations for spin/magnetization
• units: Unit validation - 14 validators for physical quantities (v0.2.0)
• error: Error handling and result types

Materials & Properties

• material: Material properties (ferromagnets, interfaces, 2D magnets, topological insulators, Weyl semimetals)

Dynamics & Transport

• dynamics: Time evolution solvers (LLG equation, RK4, Heun, adaptive methods)
• transport: Spin transport phenomena (spin pumping, diffusion)

Physical Effects

• effect: Spin-charge conversion (ISHE, SSE, SOT, Rashba, Edelstein, Spin Nernst, Topological Hall)
• magnon: Magnon propagation and spin wave dynamics
• thermo: Thermoelectric effects (ANE, thermal magnon transport, multilayers)
• texture: Magnetic textures (skyrmions, domain walls, DMI, topological charge)
• spinwave: Spin wave theory (dispersion, modes, quantization)

Specialized Physics

• afm: Antiferromagnetic dynamics for THz spintronics
• stochastic: Thermal fluctuations and finite-temperature effects
• cavity: Cavity magnonics - Hybrid magnon-photon quantum systems
• altermagnet: Altermagnetic materials (RuO2, CrSb, MnTe; spin-splitter effect, v0.3.0)
• orbitronics: Orbital Hall effect, orbital torques (v0.3.0)
• frustrated: Frustrated magnets, spin ice, kagome (v0.3.0)

Coupled Systems

• circuit: Spin circuit elements (resistors, networks, spin accumulation)
• fluid: Spin-vorticity coupling in liquid metals (Barnett effect)
• mech: Nanomechanical spintronics (Barnett, Einstein-de Haas, cantilever coupling)
• ai: Physical reservoir computing with magnon dynamics

Computational Tools

• fem: Finite element method (Delaunay mesh, iterative solvers, micromagnetics)
• memory: Memory pool allocator for high-performance simulations (v0.2.0)
• simd: SIMD-friendly batch processing for vector operations (v0.3.0)
• [parallel]: Domain decomposition and parallel sweeps (v0.3.0, feature-gated)
• builder: Type-state SimulationBuilder for validated construction (v0.3.0)

Data & Validation

• visualization: Data export (VTK, CSV, JSON, HDF5)
• validation: Experimental validation tests against landmark papers
• python: Python bindings via PyO3 (v0.2.0, optional feature)

Quick Start

use spintronics::prelude::*;

// Setup materials (YIG/Pt system)
let yig = Ferromagnet::yig();
let interface = SpinInterface::yig_pt();
let pt_strip = InverseSpinHall::platinum();

// Initialize magnetization state
let m = Vector3::new(1.0, 0.0, 0.0);
let h_ext = Vector3::new(0.0, 0.0, 1.0);

// Solve LLG equation
let dm_dt = calc_dm_dt(m, h_ext, GAMMA, yig.alpha);

// Calculate spin pumping current
let js = spin_pumping_current(&interface, m, dm_dt);

// Validate physical quantities (v0.2.0)
assert!(is_valid_magnetization(yig.ms));
assert!(is_valid_damping(yig.alpha));

// Convert to electric field via ISHE
let e_field = pt_strip.convert(interface.normal, js);

Re-exports

pub use vector3::Vector3;

Modules

afm

Antiferromagnetic Spintronics - THz Dynamics

ai

Physical Reservoir Computing with Spintronics

altermagnet

Altermagnetic spintronics

benchmark

Experimental Benchmarks and Validation

builder

Type-state simulation builder for spintronics simulations

caloritronics

Spin Caloritronics: Unified module for thermoelectric and spin-caloritronic effects.

cavity

Cavity Magnonics - Hybrid Quantum Systems

circuit

Spin circuit elements and networks

constants

Physical constants for spintronics simulations

dynamics

Magnetization dynamics solvers

effect

Spin-charge conversion effects

error

Error Types for Spintronics Library

fem

Finite Element Method (FEM) for Micromagnetic Simulations

fluid

Fluid spintronics and spin-vorticity coupling

frustrated

Frustrated magnets module

io

Input/Output Module

llg

Landau-Lifshitz-Gilbert (LLG) equation solver

magnon

Magnon propagation and spin wave dynamics

material

Material properties for spintronics simulations

mech

Nanomechanical spintronics

memory

Memory Pool Allocator for High-Performance Simulations

orbitronics

Orbitronics Module

prelude

Commonly used types and functions

simd

SIMD-friendly batch processing for Vector3 arrays

spinwave

Spin wave theory module

stochastic

Stochastic Magnetization Dynamics - Finite Temperature Effects

texture

Magnetic textures and topological structures

thermo

Thermoelectric and thermomagnetic effects in spintronics

transport

Spin transport phenomena

units

Unit consistency checks for physical quantities

validation

Physical Validity Checks

vector3

Simple 3D vector implementation for spintronics

visualization

Visualization and Data Export