It is well established that near-field radiative heat transfer (NFRHT) can exceed Planck’s blackbody limit¹ by orders of magnitude owing to the tunnelling of evanescent electromagnetic frustrated and surface modes^2,3,4, as has been demonstrated experimentally for NFRHT between two large parallel surfaces^5,6,7 and between two subwavelength membranes^8,9. However, although nanostructures can also sustain a much richer variety of localized electromagnetic modes at their corners and edges^10,11, the contributions of such additional modes to further enhancing NFRHT remain unexplored. Here we demonstrate both theoretically and experimentally a physical mechanism of NFRHT mediated by the corner and edge modes, and show that it can dominate the NFRHT in the ‘dual nanoscale regime’ in which both the thickness of the emitter and receiver, and their gap spacing, are much smaller than the thermal photon wavelengths. For two coplanar 20-nm-thick silicon carbide membranes separated by a 100-nm vacuum gap, the NFRHT coefficient at room temperature is both predicted and measured to be 830 W m⁻² K⁻¹, which is 5.5 times larger than that for two infinite silicon carbide surfaces separated by the same gap, and 1,400 times larger than the corresponding blackbody limit accounting for the geometric view factor between two coplanar membranes. This enhancement is dominated by the electromagnetic corner and edge modes, which account for 81% of the NFRHT between the silicon carbide membranes. These findings are important for future NFRHT applications in thermal management and energy conversion.

众所周知，由于瞬逝电磁受挫模式和表面模式^{2,3,4的隧道效应，近场辐射传热 (NFRHT) 可以超过普朗克黑体极限1 个}数量级，正如两个之间的 NFRHT 实验所证明的那样大的平行表面^5、6、7以及两个亚波长膜^8、9之间。然而，尽管纳米结构还可以在其角和边缘^10,11处维持更丰富的局域电磁模式，但此类附加模式对进一步增强NFRHT 的贡献仍未得到探索。在这里，我们从理论上和实验上证明了由角模式和边缘模式介导的 NFRHT 的物理机制，并表明它可以在“双纳米级状态”中主导 NFRHT，其中发射器和接收器的厚度以及它们的间隙间距，比热光子波长小得多。对于由 100 nm 真空间隙隔开的两个共面 20 nm 厚的碳化硅膜，室温下的 NFRHT 系数预测和测量均为 830 W m ^{− 2} K ^{− 1}，比普通薄膜的 NFRHT 系数大 5.5 倍。两个无限碳化硅表面由相同的间隙隔开，并且比相应的黑体极限大 1,400 倍，说明了两个共面膜之间的几何视角因子。这种增强主要由电磁角和边缘模式决定，它们占碳化硅膜之间 NFRHT 的 81%。这些发现对于未来 NFRHT 在热管理和能量转换方面的应用非常重要。