Radiative imbalance with the sky → Electrical work

Matrix context

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

D.12 × C.20 · Radiative imbalance with the sky × Photothermalfamily: PhotothermalD.12 × C.17 · Radiative imbalance with the sky × Spin caloritronicfamily: Spin caloritronic

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).

• Radiative cooling power bound · resource-bound · listed, never decisive
  net cooling power ≲ 100–150 W/m² under a clear sky
• 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
• Onsager–Casimir reciprocity · constitutive-relation · listed, never decisive
  L_ij(B) = ε_i ε_j L_ji(−B): the cross-coefficients of coupled linear transport are equal up to the time-reversal parities ε of the variables and reversal of the magnetic field; L_ij = L_ji is the zero-field, even-parity case

Steps

1. 01
   Radiative imbalance with the sky —drives→ Radiative sky coolingreplicatedclaim record

   radiative → thermal

   • an emitter with high emissivity in the 8–13 µm window and high solar reflectance
   • a clear sky; humidity and cloud close the window

   refs [1] [2] [3]
2. 02
   Radiative sky cooling —produces→ Temperature gradientreplicatedclaim record

   thermal → thermal

   • the cooled surface sits a few kelvin below ambient air

   refs [1] [4] [3]
3. 03
   Temperature gradient —drives→ Spin Seebeck effectreplicatedclaim record

   thermal → spin · loss to thermal

   • a magnetised ferromagnet, metallic or insulating (YIG), under a temperature gradient
   • an adjacent spin sink (heavy-metal layer) is needed for the usual electrical detection through inverse spin Hall conversion, not for the spin-Seebeck response itself

   solid · ferromagnet required · temperature gradient required

   refs [5] [6] [7] [8]
4. 04
   Spin Seebeck effect —produces→ Spin currentreplicatedclaim record

   spin → spin · loss to thermal

   • magnon current pumps a spin current into the adjacent metal across the interface

   refs [6] [8]
5. 05
   Spin current —drives→ Inverse spin Hall effectestablishedclaim record

   spin → electrical · loss to thermal

   • a heavy metal with strong spin–orbit coupling (Pt, Ta, W); works at room temperature

   solid · conductor required · room temperature

   refs [9] [10]
6. 06
   Inverse spin Hall effect —produces→ Charge carriersestablishedclaim record

   electrical → electrical

   refs [9] [10]
7. 07
   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 [11]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 11

1. [1]
   A. P. Raman et al.. Passive radiative cooling below ambient air temperature under direct sunlight (2014)

   Nature 515, 540–544 · doi:10.1038/nature13883 · crossref ✓ 2026-09-19 · record
2. [2]
   Y. Zhai et al.. Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling (2017)

   Science 355, 1062–1066 · doi:10.1126/science.aai7899 · crossref ✓ 2026-09-19 · record
3. [3]
   J.-l. Kou et al.. Daytime radiative cooling using near-black infrared emitters (2017)

   ACS Photonics 4, 626–630 · doi:10.1021/acsphotonics.6b00991 · crossref ✓ 2026-09-19 · record
4. [4]
   A. P. Raman, W. Li, S. Fan. Generating light from darkness (2019)

   Joule 3, 2679–2686 · doi:10.1016/j.joule.2019.08.009 · crossref ✓ 2026-09-19 · record
5. [5]
   K. Uchida, et al.. Observation of the spin Seebeck effect (2008)

   Nature 455, 778–781 · doi:10.1038/nature07321 · crossref ✓ 2026-09-19 · record
6. [6]
   K. Uchida, et al.. Spin Seebeck insulator (2010)

   Nature Materials 9, 894–897 · doi:10.1038/nmat2856 · crossref ✓ 2026-09-19 · record
7. [7]
   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
8. [8]
   M. Weiler et al.. Experimental test of the spin mixing interface conductivity concept (2013)

   Physical Review Letters 111, 176601 · doi:10.1103/PhysRevLett.111.176601 · crossref ✓ 2026-09-19 · record
9. [9]
   E. Saitoh et al.. Conversion of spin current into charge current at room temperature: Inverse spin-Hall effect (2006)

   Applied Physics Letters 88, 182509 · doi:10.1063/1.2199473 · crossref ✓ 2026-09-19 · record
10. [10]
    J. Sinova et al.. Spin Hall effects (2015)

    Reviews of Modern Physics 87, 1213 · doi:10.1103/RevModPhys.87.1213 · crossref ✓ 2026-09-19 · record
11. [11]
    N. W. Ashcroft, N. D. Mermin. Solid State Physics (1976)

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