Anomalous Nernst thermopile

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.01 × C.17 · Temperature gradient × Spin caloritronicfamily: Spin caloritronic

Measured or reported performance

Summary figures only; no datum-level record yet. Each figure below is a reviewed summary, not a single measurement.

notes

transverse thermopower of ~6 µV/K in Co₂MnGa; device power densities not yet competitive

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Carnot limit · formula-bound · hard, applies to this route
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c

Steps

1. 01
   Temperature gradient —drives→ Anomalous Nernst effectreplicatedclaim record

   thermal → electrical · loss to thermal

   • a magnetised ferromagnet or topological semimetal; no external field needed once magnetised

   solid · ferromagnet required · temperature gradient required

   refs [1] [2]
2. 02
   Anomalous Nernst effect —produces→ Charge carriersreplicatedclaim record

   electrical → electrical

   refs [1] [2]
3. 03
   Charge carriers —converts into→ Electrical workestablishedclaim record

   electrical → electrical · loss to thermal

   • carriers driven through an external load at the potential difference the source maintains

   refs [3]

Evidence for the complete composition · 1

1. [1]
   A. Sakai, et al.. Giant anomalous Nernst effect and quantum-critical scaling in a ferromagnetic semimetal (2018)

   Nature Physics 14, 1119–1124 · doi:10.1038/s41567-018-0225-6 · crossref ✓ 2026-09-19 · record

Evidence for the constituent relations · 3

1. [1]
   A. Sakai, et al.. Giant anomalous Nernst effect and quantum-critical scaling in a ferromagnetic semimetal (2018)

   Nature Physics 14, 1119–1124 · doi:10.1038/s41567-018-0225-6 · crossref ✓ 2026-09-19 · record
2. [2]
   G. E. W. Bauer, E. Saitoh, B. J. van Wees. Spin caloritronics (2012)

   Nature Materials 11, 391–399 · doi:10.1038/nmat3301 · crossref ✓ 2026-09-19 · record
3. [3]
   N. W. Ashcroft, N. D. Mermin. Solid State Physics (1976)

   Holt, Rinehart and Winston · book, no DOI · record