Thermal Emission Control via Twist Tuning of Embedded Eigenstates

Abstract: The field of thermal emission engineering shows great potential for various applications, such as lighting, energy harvesting, and imaging, using natural or artificial structures. However, existing structures face challenges in fabrication or do not provide the necessary degree of control over key parameters such as emission intensity, spectral composition, and angular distribution. To address these limitations, we propose a novel approach that leverages in-plane hyperbolic response, embedded eigenstates enabled by epsilon-near-zero, and exceptional tunability through twisting in {\alpha}-MoO3 heterostructures. By adjusting the twist angle, we can manipulate the system's properties, transforming it from a near-perfect reflector to a perfect absorber. This enables us to exert control over thermal emission power, spanning an order of magnitude. Furthermore, our research has uncovered a significant angular dependence of thermal emission, which varies with relative rotation.