Spin-selective thermal radiation with near-perfect circular dichroism in twisted hyperbolic materials

Spinning thermal radiation is a unique phenomenon in the symmetry-broken system, which is of both fundamental and applied interest. Its potential applications include chiral nanoparticle probing and radiation detection. However, these applications are often restricted by limited circular dichroism and quality factor. In this paper, the spinning thermal radiation of twisted hyperbolic heterostructures is investigated. By adjusting the twist angle, we demonstrate the near-perfect circular dichroism (CD = 0.99) and the high quality factor at a wavelength of 20 μm. The epsilon-near-zero mode of α-phase molybdenum trioxide allows for excellent spin-selective thermal radiation. The co-polarization and cross-polarization have proven it in the reflected wave and the distribution of the electric field components. The strong spinning thermal radiation originates from the cross-polarization conversion between the left-handed circularly polarized and right-handed circularly polarized waves. This work provides a general approach to spinning thermal radiation for future energy applications.