Optimization of a Weyl-semimetal-based near-field heat transfer system

Abstract

Near-field radiative heat transfer (NFRHT) is inherently limited by Lorentz reciprocity, which can be partially mitigated through the application of an external magnetic field. However, recent studies have discovered that Weyl semimetals (WSMs) possess the ability to achieve nonreciprocal surface plasmon polariton modes without relying on an external magnetic field. Building upon the nonreciprocal nature of WSMs, this study investigates NFRHT between two WSM slabs and compares different WSM materials. The primary focus of the comparison lies in analyzing the heat flux under varying emitter and receiver temperatures. Three of the selected WSM materials exhibit similar performance in NFRHT, showing sensitivity to a decrease in the receiver temperature due to their low dielectric tensor components. In contrast, Eu2IrO7 displays distinctive characteristics, being sensitive to changes in the emitter temperature as a result of its higher dielectric tensor components. Additionally, a reassessment of the nonreciprocity in Co2MnGa, Eu2IrO7 and Co3Sn2S2 is conducted. Furthermore, Bayesian optimization algorithms are employed to optimize parameters and address the challenge of low thermal radiation observed in existing WSM NFRHT systems. The results highlight the achievement of an optimal WSM material that achieves an impressive heat flux of 5.29 × 108 (W/m2) at an emitter temperature of 310 K and a receiver temperature of 290 K. Notably, this heat flux surpasses that of Co2MnGa by 2.5 times in the context of NFRHT. The discoveries presented in this study promises to offer practical implications for the development of nonreciprocal thermal energy management systems.