Claude · model → Effort

Choose the model, then adjust Effort.
The screenshot shows High.
FDM · FEM · EIGENMODES
Mateusz Zelent1,2
Mateusz Gołębiewski2 · Uladzislau Makartsou2 · Philipp Pirro1
1 RPTU Kaiserslautern–Landau
Department of Physics & OPTIMAS
2 Adam Mickiewicz University, Poznań
Institute of Spintronics and Quantum Information
A provider, a model, a reasoning setting and a subscription are different choices.
| Provider | Efficient / focused | Everyday work | Demanding work |
|---|---|---|---|
| OpenAI | GPT-6 Luna MAX Extraction, repeated edits | GPT-6.1 Terra: visual work / writing GPT-6.1 Sol: analysis / coding | GPT-6 Astra Difficult synthesis and decisions |
| Anthropic | Haiku 5.5 Fast, bounded tasks | Sonnet 5.5 · general work Opus 5.5 · demanding agent work | Fable 5.1 Frontier coding / agentic work |
| Gemini 3.5 Flash-Lite · routine intake | Gemini 3.8 Flash · general agent work | Gemini 4 Argon · flagship; 3.1 Pro Preview · preview |
Starting recommendations — validate on your own papers, scripts and numerical checks.
Reasoning effort trades response time and token use for deeper analysis.

Choose the model, then adjust Effort.
The screenshot shows High.
For Luna, always choose MAX. For other models, adjust effort to the task and check quality, time and usage.
Select the actual model and effort; a prompt saying “think harder” is not a settings change.
| Surface | What to choose | Practical use |
|---|---|---|
| ChatGPT Chat | GPT-6 thinking slider; eligible Pro uses Astra | Bounded analysis, explanation and research |
| ChatGPT Work / Codex | Astra / Sol / Terra: choose effort; Luna: always MAX | Files, applications and project execution |
| Claude / Claude Code | Available family and effort in the account selector | Same task contract; different tool access |
| Gemini app / API | App mode or exact API model ID | Do not equate a subscription name with a model |
Pro subscription ≠ Pro model / effort ≠ Deep Research. Availability varies with plan, client and rollout.
Route the work by difficulty and cost of error.
| Research task | Starting choice | Escalate when… |
|---|---|---|
| Extract DOI, units or table fields | Luna MAX / Haiku / Flash-Lite | The source is ambiguous or multimodal |
| Rewrite a paragraph; inspect figures | Terra / Sonnet / Flash | Meaning, evidence or notation conflicts |
| Debug analysis; compare methods | Sol / Opus / Gemini Pro | The cause spans files or assumptions |
| Derive a model; challenge a research plan | Astra / Fable / Argon; bounded strong reasoning | An independent check still finds contradictions |
One workflow can use several models: strong planner → economical executor → focused independent check.
Personality controls tone. Instructions define the working rules.
ChatGPT: Settings → Personalization → Base style and tone / custom instructions.
Claude: profile preferences, response styles and project instructions.
Project: keep symbols, methods and constraints with the project.
Use concise scientific English and SI units. Preserve citation keys and uncertainty. Separate evidence from interpretation. Never invent references or measurements. Flag missing sources and check limiting cases.
A transparent estimate using GPT-6.1 Sol — the model I use most.

Displayed account total · mostly Sol, according to the author.
| Illustrative token mix | Estimated cost |
|---|---|
| 90% input / 10% output · no cache | $751k |
| 90% input / 10% output · 90% input cache hits | $350k |
| 99% input / 1% output · 90% input cache hits | $117k |
USD / 1M: input $2 · output $10 · cache read $0.10 · 30-minute cache write $2.50.
Estimates, not a bill. Standard tier; ≤272K input/request. Cached variants count misses as cache writes. Excludes tools and tax.
Official API pricing · checked 28 Oct 2026USD per 1M tokens · standard direct API · checked 28 October 2026
| Model | Input | Output | Cached input |
|---|---|---|---|
| GPT-6 Luna | $0.10 | $0.50 | $0.01 |
| GPT-6.1 Terra | $1 | $5 | $0.05 |
| GPT-6.1 Sol | $2 | $10 | $0.10 |
| GPT-6 Astra | $10 | $50 | $1 |
| Claude Haiku 5.5 | $0.10 | $0.50 | $0.01 |
| Claude Sonnet 5.5 | $2 | $10 | $0.10 |
| Claude Opus 5.5 | $4 | $20 | $0.20 |
| Claude Fable 5.1 | $10 | $50 | $0.25 |
OpenAI: ≤272K input tokens. Haiku: ≤100K total prompt; above this, input/output becomes $0.50/$2.50. Tools, cache writes and other tiers are extra.
Current paid Developer API text rates · promotional changes are explicit.
| Model | Input / output per 1M | Status / condition |
|---|---|---|
| Gemini 4 Argon | $2 / $10 | Introductory through 30 Nov 2026; then $4 / $20 |
| Gemini 3.8 Flash | $0.75 / $3.75 | Introductory through 31 Dec 2026; then $1.50 / $7.50 |
| Gemini 3.5 Flash-Lite | $0.30 / $2.50 | Stable |
| Gemini 3.1 Pro Preview | $2 / $12 | ≤200K prompt; above: $4 / $18 |
| Gemini 3.1 Flash-Lite | $0.25 / $1.50 | Earlier stable option; text / image / video |
Thinking is included in billed output. Caching, storage and grounding have their own accounting. App subscriptions use separate access rules.
Carry preferences forward without turning recollection into evidence.
Ask: “What do you remember about this project?” Correct stale details.
Use: CONTEXT.md, DECISIONS.md, references.bib.
ChatGPT web memory and local Codex memory are separate stores. Do not assume automatic transfer to VS Code.
Instructions + reference material + optional scripts — loaded when relevant.
claim-audit/ SKILL.md references/checklist.md assets/audit-template.csv scripts/check_citations.py
Different roles: skill = procedure; project = context; connector = access; model = reasoning engine.
Test the procedure on one known manuscript before reusing it across the group.
Keep style, memory, project rules and skills separate.
| Need | Chat / application | Local project |
|---|---|---|
| Preferred language and tone | Personal preferences / style | Personal agent instructions |
| Remember recurring context | Memory, if enabled and in scope | Codex host memory / Claude Code auto memory |
| Enforce project conventions | Project instructions and knowledge | AGENTS.md / CLAUDE.md; checked-in methods |
| Repeat a procedure | Supported skill / custom assistant / Gem | SKILL.md with references and scripts |
Chat history, local memory and project files are not automatically synchronized across products.
Use one skill for a specific stage; these are available examples, not universal built-ins.
| Skill | When to invoke it | Useful result |
|---|---|---|
| idea-refine · brainstorming ↗ | An idea is still vague | Alternative directions + assumptions + smallest test |
| planning-and-task-breakdown ↗ | The direction is chosen | Ordered tasks, dependencies and acceptance checks |
| debugging-and-error-recovery ↗ | A script or numerical result is wrong | Reproduction → cause → targeted fix → verification |
| code-review-and-quality ↗ | Before trusting an analysis change | Prioritized findings with file locations and evidence |
| source-driven-development ↗ | Using an unfamiliar library / API | Implementation grounded in official documentation |
| claim-audit · included template ↗ | Checking a manuscript draft | Claim–source table; unsupported claims flagged |
Discover → inspect the source → install selectively → test on a small example.
Browse skills.sh ↗ or ask an available find-skills skill ↗.
npx skills find brainstorming npx skills find literature review
Read SKILL.md, scripts, dependencies and license. Check author and maintenance. Popularity alone is not a quality guarantee.
npx skills add addyosmani/agent-skills --list npx skills add addyosmani/agent-skills --skill idea-refine
Run in your project; select the intended agent. Then ask it to list available skills and use the exact installed name.
“Find a skill for checking manuscript claims against source PDFs. Compare three options by source, workflow, dependencies and output. Show links before installing anything.”
Example: idea-refine ↗ · Alternative: Superpowers brainstorming ↗
Use the available idea-refine skill. We want to study spin-wave confinement in a YIG waveguide. We have four weeks, existing simulation tools and no new measurements.
Ask up to three clarifying questions. Propose five distinct directions. Compare scientific value, feasibility and the hardest assumption. After I choose, propose the smallest discriminating test.
Expected output: comparison table → chosen hypothesis → test and failure criterion.
Novelty is a hypothesis until checked against literature.
Use deep analysis to produce a handoff that another agent can execute.
Use Pro / strong reasoning for a bounded derivation. Use Deep Research for source discovery and synthesis.
brief.md methods.md evidence.csv references.bib open_questions.md report.pdf
Download a ZIP, inspect it, open the folder in VS Code or attach it to Work.
Implement one specific analysis or revision.
“Read brief.md and methods.md. Implement only Figure 2. Preserve inputs. Run unit and limit checks; return the diff and reproduction command.”
Download the templates; replace the examples with your verified project facts.
brief.md accepted_methods.md evidence.csv references.bib open_questions.md README.md
PDF for reading · editable sources for execution · ZIP for transport.
Read the brief and source manifest. List missing inputs. Implement only the agreed analysis. Preserve raw data. Return a diff, reproduction command and checks actually run.
Put the manuscript, data, scripts, figures and agent in one reviewable project.

Use Codex or Claude Code; the extensions and memory scopes are distinct.
Attach the raw data, units, method and one known reference case.
Read brief.md, dispersion.csv and units.md. Write a script that plots frequency in GHz against wave number in rad/µm. Preserve the raw CSV. Use only the analytical expression supplied in methods.md; flag undefined parameters before implementation.
Return the code diff, figure and reproduction command. Check missing columns, unit conversions and the k = 0 limit against the supplied reference. Report checks actually run, and label anything you could not verify.
Acceptance: rerun the command, inspect units and independently check the reference value. A plausible-looking plot is not validation.
Start from a clean copy of the Overleaf source and keep the original recoverable.
The source ZIP does not include the compiled PDF.
main for new clones.Confirm remote + branch. Git pushes can displace active comments or Track Changes.
VS Code extension for an editor panel, or the CLI for a terminal session.
Cmd/Ctrl + Shift + X.Requires VS Code 1.94 or later.
# macOS / Linux / WSL
curl -fsSL https://claude.ai/install.sh | bash
# Windows PowerShell
irm https://claude.ai/install.ps1 | iex
Open a new terminal after installation; sign in on first run.
Terminal commands start the tool; slash commands control a running conversation.
cd /path/to/paper
claude
Open the prompt in the manuscript’s project directory.
/init
Review the proposed starter CLAUDE.md before you rely on it.
Use /init in the session — not claude init in the shell.
Put stable manuscript conventions and boundaries in the project’s CLAUDE.md.
# Paper workflow
- Main file: main.tex
- Bibliography: refs.bib
- Preserve claims, values, units, and cite keys.
- Never invent data or references.
- Edit only the requested section.
- Ask before changing figures or .bib files.
Replace the example filenames with this project’s real files.
A project skill is a Markdown workflow Claude can discover or you can invoke by name.
.claude/skills/revise-paragraph/SKILL.md
---
name: revise-paragraph
description: Revise one selected paragraph for clarity while preserving its meaning.
---
1. Edit only the named paragraph.
2. Preserve claims, numbers, units, and cite keys.
3. Add no sources; show a diff first.
/reload-skills
/skills
/revise-paragraph
Use the skill list to confirm what this project exposes.
For external discovery, browse skills.sh ↗; treat entries as third-party candidates.
Ask for an evidence-bound edit that is easy to compare with the source.
“Revise only the Results paragraph in sections/results.tex. Preserve every scientific claim, number, unit, and citation key. Add no sources or data. Show a diff and wait for my approval before applying the edit.”
A clean build checks syntax and references; it does not validate the science.
/diff
# local TeX installation
latexmk -pdf main.tex
Or click Recompile in Overleaf. Check the PDF and build log.
Keep ZIP handoffs separate; send Git changes to the confirmed target.
The original project remains a separate project.
main/master.New clones use main; older ones may use master. Full command sequence →
If the push is rejected or conflicts appear: stop, sync, review again. Never force-push a manuscript handoff.
Complete tutorial, copyable examples & official sources →One concrete manuscript request is more useful than “improve my paper”.
Ask the agent to list files it could actually read.
Revise the Introduction only. Preserve scientific claims, uncertainty and citation keys. Return a diff and a claim–source table. Mark unsupported claims; do not invent references.
The same task — a vague request versus clear instructions you can verify.
Improve my paper.
No target section, source of truth, permitted changes or review format.
Introduction.tex
references.bib
the cited PDFs
Revise only Introduction.tex for clarity; keep it under 700 words. Preserve scientific claims, uncertainty, equations and citation keys.
Use the attached papers as evidence. Flag unsupported claims with the source passage or “source missing”.
Return a diff and a claim–source table. List unreadable files. Check that every citation key exists in references.bib.
Attach your question, inclusion criteria, seed papers and search cutoff.
Find studies comparing finite-difference and finite-element methods for spin-wave dispersion in confined waveguides. Search through [date]. Include primary papers with an explicit geometry, material parameters and a numerical or experimental reference. Exclude papers that only mention the methods.
Return a table: citation / DOI, geometry, method, validation, limitations and supporting page or passage. Separate full texts you inspected from abstract-only records. Do not invent missing values. End with unresolved questions and a reproducible search log.
Acceptance: verify DOI/title matches and inspect the source passages for three key claims. A search is not necessarily exhaustive.
API tokens, subscription allowance and benchmark cost are different measures.
20,000 input + 5,000 billed output tokens
No cache, tools or retries
| OpenAI model | Estimated text cost |
|---|---|
| Luna MAX | $0.0045 |
| Terra | $0.045 |
| Sol | $0.09 |
| Astra | $0.45 |
Measure: cost per accepted result, plus your review time.
Attach the derivation, assumptions, figure and numerical settings.
Review the attached derivation and dispersion comparison as a critical colleague. Separate algebra, dimensions, physical assumptions and numerical error. Check boundary conditions, k = 0 and the stated limiting case.
Return findings ordered by scientific impact, each with a source location, explanation and a concrete test. Do not silently fix the derivation. Distinguish a confirmed error from a question requiring more evidence. Suggest the single most informative next check.
Acceptance: resolve each material finding with an independent calculation or source; agreement between models is not sufficient.
Read each score together with its task, reasoning setting and cost definition.
A second cost model · the supplied mypriors.com chart compares index score and subscription cost per task

Higher score at lower estimated cost is attractive within this comparison.
Sol high, Astra max and Claude variants occupy different score–cost positions.
Subscription cost per task is not API token pricing or a guaranteed marginal fee.
User-supplied chart · OpenAI vendor-reported benchmark · compare within this test.

Read the model, reasoning setting, task suite and cost definition together. This is not an independent scientific-research ranking.
User-supplied chart · OpenAI vendor-reported benchmark · compare within this test.

Read the model, reasoning setting, task suite and cost definition together. This is not an independent scientific-research ranking.
Vals AI · Terminal-Bench 4.0 · 26 October 2026 · Mini-SWE-agent
| Model | Score | Reported cost / test |
|---|---|---|
| Claude Opus 5.5 | 65.15% | $13.20 |
| Claude Sonnet 5.5 | 64.14% | $16.51 |
| Claude Fable 5.1 | 58.08% | $17.18 |
| Gemini 4 Argon | 57.58% | $17.64 |
| Claude Haiku 5.5 | 36.36% | $3.12 |
Same evaluator and harness, selected rows. Different samples and settings from the OpenAI chart. Measure your own accepted outputs.
Start economical; spend stronger reasoning where a failed answer is costly.
Attach the relevant sections; search before reading entire folders.
Ask for a patch, table or decision — not repeated full reports.
Summarise accepted facts and open issues before starting a new task.
Strong model for the plan; smaller model for explicit repetitive steps.
Do not repeat unchanged searches or tests. Recheck after relevant changes.
Include retries, tool calls, review and corrections in the total cost.
A research platform for finite-difference and finite-element micromagnetics.
From magnetic textures and dynamics to eigenmodes and dispersion.
RPTU Kaiserslautern-Landau, Germany
Department of Physics & OPTIMAS
Adam Mickiewicz University, Poznań, Poland
Faculty of Physics and Astronomy
Funded byMateusz Zelent acknowledges funding from the European Union's Horizon Europe programme under HORIZON-MSCA-2024-PF-01, Marie Skłodowska-Curie Grant Agreement No. 101208951 (CNMA).
Start with the research question — then choose the geometry, physics and numerical method.
Add interactions and study magnetic textures, coupled structures and spin-wave modes.
Use regular grids for films and multilayers, or conforming meshes for curved and complex geometries.
Carry one study from model setup through execution to field maps, spectra and reproducible results.
Mateusz Zelent began FullMag in April, using AI assistance from the start.
Start building a micromagnetics platform around real research needs.
Connect scientific reasoning, implementation, debugging and documentation.
FDM + FEM, Python + Control Room, dynamics + spectral analysis.
ChatGPT · Codex
AI model provider
ClaudeChat · coding assistance
GeminiGoogle AI

FDM = finite differences · FEM = finite elements. Both approximate the same continuum magnet.
| Question | FDM · regular cells | FEM · unstructured mesh |
|---|---|---|
| How is the sample represented? | Magnetization on cuboid cells; surfaces cut by an active mask | Magnetization expanded in nodal basis functions on mesh elements |
| How are derivatives computed? | Neighbour stencils and face differences | Integrals of basis functions and their gradients: the weak form |
| How is demagnetization computed? | Nonlocal tensor convolution, accelerated by FFT | Scalar-potential PDE; finite airbox or FEM–BEM open-boundary treatment |
| Where is it attractive? | Extended films, regular waveguides and repeated GPU workloads | Curved boundaries, local refinement and complex 3D geometry |
| What must converge? | Cell size, boundary representation and time step | Mesh size/order, exterior treatment and linear-solver tolerance |
A research platform joining micromagnetics, solver development and inspectable workflows.
| Fullmag | MuMax3 | COMSOL | |
|---|---|---|---|
| Core approach | One model; FDM and FEM execution paths | Specialized GPU finite-difference micromagnetics | General finite-element multiphysics; micromagnetics requires a suitable formulation/module |
| Research advantage | Own operators, new interactions, mesh/grid choice and analysis products | Established reference for films, dynamics and micromagnetic benchmarks | Geometry, coupled PDEs and multiphysics modelling tools |
| Workflow | Python + Control Room → shared model → plan → saved results | Scripted simulation and output analysis | Model/study setup with configurable solvers |
| Trade-off | We maintain physics, cross-language interfaces and qualification | Grid representation must resolve curved boundaries | Licensing, model setup and solver choices; no universal performance comparison |

A shared scientific description feeds separate numerical implementations.
| Layer | Technology | Responsibility in Fullmag |
|---|---|---|
| Author the experiment | Python DSL · NumPy · optional Gmsh | Geometry, materials, interactions, staged studies and mesh preparation |
| Validate and plan | Rust · typed ProblemIR and ExecutionPlan | Resolve FEM/FDM, CPU/GPU, precision and supported combinations |
| Execute and record | Rust runner · C ABI into native backends | Run lifecycle, output streams, field data and provenance; Rust also owns the FDM CPU reference engine |
| Compute fields and evolve m | C++/MFEM and CUDA | FEM operators/solves; FDM CUDA stencils, cuFFT demag and integrators; FEM device kernels where supported |
| Inspect the science | TypeScript · React/Next · Three.js · ECharts | 3D geometry/fields, dispersion curves, result tree and controls; Axum/Tokio provide the Rust API |
The state is the unit magnetization m(r,t); material parameters set the competing length and time scales.
Exchange penalizes rapid spatial changes; the discretization turns this energy into a field.
These terms change the energy and effective field; their numerical realization depends on the solver.
| Interaction | Physical effect | Current implementation scope |
|---|---|---|
| Exchange | Penalizes neighbouring spins pointing differently | FDM CPU/CUDA; FEM weak operator; multilayer intralayer exchange |
| Uniaxial + cubic anisotropy | Preferred axes / crystal directions | FDM and FEM paths; material-field and topology restrictions are lane-specific |
| Zeeman + demagnetization | Applied field + nonlocal self-field | Uniform Zeeman; FDM FFT / multilayer convolution; FEM Poisson / FK |
| Interfacial DMI | Chiral gradients linked to an interface normal | Single-grid FDM; FEM source paths; multilayer global +z interfacial model |
| Bulk DMI | Chiral volume gradients, m·curl(m) | Single-grid FDM and FEM source paths; public multilayer rejects bulk DMI |
| Rotated interfacial DMI | Fixed chiral operator for in-plane-background textures | Implemented FDM/FEM CPU/GPU within explicit topology/boundary gates |
| Prescribed-strain magnetoelastic field | Strain modifies magnetic energy | Internal reference operators; not a qualified coupled mechanics solver |
A direct torque is a rate in s⁻¹; an effective field is in A/m. They enter LLG differently.
| Mechanism | What it represents | Current scope / important boundary |
|---|---|---|
| Prescribed SOT | Field-like and damping-like spin-orbit torques | CPU reference and bounded CUDA/FEM paths; prescribed SOT is not a solved spin-Hall transport model |
| Slonczewski STT | Spin-polarized current acting on a thin magnetic layer | Bounded fullmag.v2 local target-masked routes; interface-flux variant unsupported |
| Zhang–Li STT | Current couples to magnetization gradients | Separate formula/version contracts: MuMax3-v1 SP5 evidence does not validate Fullmag-v1 or every lane |
| Thermal Brown noise | Stochastic field determined by temperature, damping, volume and time step | Single-grid FDM CPU/GPU; FEM and public multilayer thermal are not executable here |
| Oersted field / current transport | Magnetic field generated by a declared or computed current | Named cylinder and prescribed-density paths; separate antenna field-solve workflow |
| RKKY / interlayer exchange | Exchange coupling across layers | Python/IR objects exist; current planner rejects executable coupling |
A distinct chiral energy for in-plane-background textures such as bimerons — not merely a rotated easy axis.
RotatedInterfacialDMI(D) selects this fixed operator.anisU sets anisotropy separately; it does not rotate DMI.From magnetic textures to relaxation, a held state and energy diagnostics.
Every magnetic cell contributes to the field in every other cell; FFTs accelerate this long-range sum.
Each destination layer receives a field from every source layer through its own oriented pair kernel.
| Stage | Operation | Why it is needed |
|---|---|---|
| 1 · Native magnetization | Mⱼ = Mₛ,ⱼmⱼ → common scratch representation | Preserve the physical magnetic moment when layouts differ |
| 2 · Transform | Pad and FFT each source layer | Reuse a source spectrum across its destination layers |
| 3 · Couple ordered pairs | Accumulate Nᵢⱼ Mⱼ for every j → i | Kernel includes source/destination thickness and physical offset |
| 4 · Recover fields | Inverse FFT, crop and pull back to native layer | Return Hᵢ on the actual magnetic cells, not on an artificial spacer grid |
The CPU descriptor path and CUDA path have different current coverage.
| two_d_stack | three_d | |
|---|---|---|
| Layer representation | One native z cell per layer, unless explicitly averaged | Several z cells per volumetric layer |
| Transform | 2D FFT in x/y; scratch z extent = 1 | 3D pair convolution over signed x/y/z lags |
| Thickness and gaps | Independent thickness and centre offsets; shared in-plane cell pitches required | Layer origins retained; translational cell pitches must match for FFT pairs |
| Meaning | No fictitious magnetic cells in a spacer | Resolves magnetization variation across layer thickness |
Magnetization creates a potential; the surrounding air is part of the computational mesh.

FK combines volume finite elements with a boundary-element description of the exterior.
| Step | Mathematical task | Fullmag realization |
|---|---|---|
| 1 · Volume source | Δu₁ = ∇·M; ∂ₙu₁ = M·n | Neumann FEM solve; one gauge constraint per connected component removes the constant null mode |
| 2 · Exterior contribution | u₂|Γ = B(u₁|Γ) | Boundary trace → hierarchical BEM operator; near interactions evaluated directly, far interactions compressed |
| 3 · Harmonic correction | Δu₂ = 0 in the magnet | Second FEM solve with boundary values from B; combine and recover −∇u |
| 4 · Energy | E_d = −(μ₀/2)∫ M·H_d dV | Integrate on the magnetic body; the exterior is accounted for by the boundary operator |
Both are implemented; they make different geometric and algorithmic trade-offs.
| Poisson airbox | Fredkin–Koehler FEM–BEM | |
|---|---|---|
| Unknowns / exterior | Potential on magnet + meshed air | Body potentials + boundary integral; no airbox |
| Main error controls | Body mesh, air mesh, outer radius and boundary condition | Body/surface mesh, quadrature and far-block compression |
| CPU path | MFEM assembly + HYPRE scalar solve | Two sparse HYPRE solves + hierarchical surface apply |
| GPU path in source | CUDA/CSR RHS and recovery + device-HYPRE Poisson | Uploaded BEM hierarchy + CUDA apply + two device-HYPRE solves |
| Current FK restrictions | Separate periodic Poisson realization exists | 3D body-only TET4/P1; nonperiodic; oriented, watertight boundary |
| Validation status | Scoped evidence; do not generalize a periodic k=0 pass | CPU/GPU implementation present; current physics qualification remains NOT VERIFIED |
A surface condition for magnetization is different from a boundary condition for the stray-field potential.
| Boundary / field | Condition and meaning | Consequence for simulation |
|---|---|---|
| Free exchange surface · m | ∂ₙm = 0 when exchange alone supplies the surface variation | No imposed surface twist; do not reuse this blindly when DMI is active |
| Exchange + DMI · m | Natural boundary balances exchange gradient and chiral boundary term | Edge canting is part of the model, including rotated DMI |
| Fixed / frozen magnetization | Selected magnetization is constrained by the authored condition | Changes admissible dynamics and mode shapes; a pinned mode condition is not an airbox condition |
| Periodic sample · m | Match paired boundaries; waves acquire a Bloch phase in eigensolve | Boundary pairing and translation must be defined consistently |
| Open exterior · u | Poisson: finite outer condition. FK: boundary integral for the exterior | Changes demag accuracy and, therefore, equilibrium and frequencies |

These algorithms answer different questions even when they reuse the same effective-field operators.
| Task | Numerical idea | What to inspect |
|---|---|---|
| Run dynamics | Integrate LLG with the selected stepper and time/error control | m(t), energy, torque and temporal convergence |
| Relax with LLG | Suppress precession / follow damping towards a stationary state | Stopping criterion and the final torque; elapsed relaxation time is not a physical transient |
| Minimize energy | Projected gradient / Barzilai–Borwein choices where admitted | Energy descent, unit-length constraint and termination reason |
| Prepare an eigenproblem | Accept a stationary state and its effective field | A residual equilibrium torque contaminates the linearization |
Fullmag contains explicit stepping and relaxation paths in Rust/CUDA and native FEM, with different admissible integrator/precision combinations. A solver name alone does not specify the run.
Different random seeds, minimizers or stop rules can choose different metastable states, explaining part of the hysteresis differences shown next.

The current distribution and conductor geometry determine the spatial Oersted field applied to the magnet.


| Stage | What is computed | Why it matters |
|---|---|---|
| Conductor / current | Charge-transport solution and conservative current representation | The return path and terminal conditions affect the generated field |
| Field operator | Direct tetrahedral Biot–Savart quadrature or bounded vector-potential FEM route | Computes the field in the target region; not a full-wave radiation claim |
| Magnetic excitation | Sample/project the saved field basis; apply the declared drive | A spatially nonuniform drive selects which modes are excited |


Two views of the airbox: the magnetostatic field extends beyond the magnetic material.



A field sweep follows metastable states, so preparation and stopping rules can shift switching events.

The figure reports different random initial states, relaxation/minimization algorithms and stop criteria. These differences need controlled comparison before attributing a shift to one field operator.

A separate solver family built around a linearization of the magnetic equations.
A mode perturbs the equilibrium only in directions perpendicular to m₀.
Free, pinned and Bloch-periodic boundaries represent different physical experiments.
| Condition on δm | Meaning | Effect |
|---|---|---|
| Free: ∂ₙδm = 0 | Natural exchange boundary without additional surface torque | Boundary spins can precess |
| Pinned: δm = 0 | Dynamic motion suppressed on the selected boundary | Changes standing-wave profiles and eigenfrequencies |
| Periodic at k = 0 | Equal values on corresponding boundary points | The same oscillation repeats in each cell |
| Bloch/Floquet | δm_dst = exp(−ik·Δr) δm_src | Neighbouring cells have a controlled phase shift; scanning k gives dispersion |
k [rad/m] is the wavevector; Δr [m] is the cell translation. The tangent-frame map matters when local bases differ.
The static demag field sets the equilibrium; its linear response belongs inside the eigen-operator.
Separate source capabilities, admitted workloads and numerical qualification.
| Path | Available in the current source | Boundary of the claim |
|---|---|---|
| FEM CPU | Eigenmodes, k-path orchestration, dense small-problem oracles and selected PETSc/SLEPc routes | Gamma/free and explicit Floquet payload gates; general selected windows require Full2x2 and ignored damping |
| FEM CPU dynamic demag-k | Shared-domain Floquet-airbox assembly boundary | Source-visible CPU bridge; no current-main managed qualification established |
| FEM GPU | K0 shared-domain PETSc/SLEPc path; narrow K0/no-demag cuSolverDN Kittel route | Not a general GPU modal solver; nonzero-k GPU routes remain gated |
| FDM CPU / GPU | Time-domain trajectories and postprocessed spectra | No native FDM eigen solver in this contract |
| Spectrum selection | Targeted eigenpairs near a requested frequency | Nearest modes do not certify a complete frequency window |

A k-path is a sequence of distinct eigenproblems, not a single frequency spectrum.

Do the thickness, material, equilibrium, exchange and exterior conditions match? Track modes consistently and check spatial/solver convergence.
This recorded case comes from its source thread; it is not a fresh execution of today’s main checkout.


A frequency alone does not tell us whether a mode is edge-localized, uniform or confined across the waveguide.

Reconstruct Re[δm exp(iωt)]. The eigenvector normalization is arbitrary until an amplitude convention or driven response is specified.




Follow the recorded views; local demonstration servers are not part of this public presentation.
The bright lines in an FFT depend on how the sample was excited and observed.

Find the natural frequencies and spatial eigenvectors directly around equilibrium. A mode can exist even if the chosen antenna couples to it weakly.

One workspace connects model construction, solver selection and published results.

Python and the UI converge on the same problem description. A saved result should remain inspectable after the solver has stopped.









Implementation breadth is real; qualification must remain attached to a named numerical workload.
| Area | Current source / demonstrated material | Development focus |
|---|---|---|
| FDM dynamics | Rust CPU reference; CUDA single-grid FP32/FP64; supplied MuMax3 comparison | Controlled error metrics and broader matched cases |
| FDM multilayer | Ordered-pair convolution, native geometries and CPU transfers; CUDA components | Descriptor parity, unequal-thickness end-to-end cases, device qualification |
| FEM demag | Airbox Poisson and hierarchical FK CPU/GPU implementations | Per-realization accuracy, exterior convergence and managed GPU evidence |
| Interaction coverage | Conservative fields, rotated DMI, bounded torques/current routes | Close workload-specific gaps rather than claim every combination |
| Eigensolve | Separate FEM linearized solver family with boundary/k-path machinery | Nonzero-k dynamic demag, native sparse paths and mode qualification |
| Workflow | Python / UI authoring, saved data, dispersion and mode inspection | Make method, units, boundary conditions and provenance visible |
Choose a scientific question, then choose the numerical experiment that can answer it.
Up = higher score; left = lower cost. The cost axis is logarithmic.
More reasoning can improve the score, with diminishing gains near the top.
Use this benchmark to shortlist settings, then test your own research tasks.