Radiative Corbino effect in nonreciprocal many-body systems

When a magnetic field is applied in the perpendicular direction to a metallic disk under the action of a radial bias voltage, a tangential electric current superimposes to the radial current due to the presence of the Lorentz force which acts on electrons. Here we introduce a thermal analog of this Corbino effect in many-body systems made of nonreciprocal bodies which interact by exchanging photons in near-field regime. In systems out of thermal equilibrium with a radial temperature gradient, we demonstrate that the Poynting field in the Corbino geometry is bent in presence of an external magnetic field, giving rise to a tangential heat flux. This thermomagnetic effect could find applications in the field of thermal management and energy conversion at nanoscale.

💡 Research Summary

The authors introduce a thermal analogue of the electronic Corbino effect, demonstrating that a magnetic field can bend the radiative heat flux in a non‑reciprocal many‑body system, thereby generating a tangential heat current. The system consists of a circular arrangement of magneto‑optical InSb nanospheres placed on three concentric rings: an inner ring (temperature T_I = 350 K), an outer ring (temperature T_O = 300 K, also the temperature of the surrounding bath), and a middle ring whose particles are allowed to reach a stationary temperature T_M. Each sphere has radius r_p = 100 nm and the inter‑particle spacing in the inner ring is five times this radius. A static magnetic field B is applied perpendicular to the plane of the disk.

In the presence of B, the permittivity tensor of InSb becomes non‑diagonal, ε(ω)=⎡ε₁−iε₂ 0; iε₂ ε₁ 0; 0 0 ε₃⎤, where ε₁, ε₂, ε₃ depend on the longitudinal and transverse phonon frequencies, the plasma frequency, and the cyclotron frequency ω_c = eB/m*. This anisotropy renders the particle polarizability α_j(ω) non‑reciprocal, which, together with the vacuum Green tensors G_EE and G_HE, yields transmission coefficients T_{jk}(ω) that satisfy T_{jk} ≠ T_{kj} when B ≠ 0.

Using the Landauer formalism for N‑body radiative heat transfer, the net power absorbed by particle j is
P_j = ∫₀^∞ (ℏω/2π) ∑_k