We propose a thermal modulation structure composed of two identical Weyl semimetal (WSM) slabs separated by a nanoscale vacuum gap. Following Maxwell's equations and the dielectric tensor of the WSM, we derive the reflection matrix at the WSM/vacuum interface. Based on fluctuation electrodynamics, the effects of the Fermi level, the number of Weyl nodes, the separation between Weyl nodes and the thickness of vacuum gap on the heat transfer coefficient and the thermal modulation contrast are numerically discussed. It is found that the WSM possesses stronger near-field radiative ability in the low frequency region, where the coupled surface plasmon polaritons between the WSM slabs play a dominant role. By continuously tuning the Fermi level from 0.01 to 0.15 eV, a large modulation contrast as high as 58.5 is obtained at T = 300 K, while in the low temperature interval [50,160] K, the minimum modulation contrast can exceed 198 for a vacuum gap of 20 nm. The obtained results might be helpful in designing a WSM-based thermal modulator with giant modulation contrasts.

我们提出了一种热调制结构，该结构由两个相同的Weyl半金属（WSM）平板组成，并由纳米级真空间隙隔开。遵循麦克斯韦方程和WSM的介电张量，我们得出WSM /真空界面处的反射矩阵。基于波动电动力学，数值研究了费米能级，韦尔节的数量，韦尔节之间的间距以及真空间隙厚度对传热系数和热调制对比度的影响。发现WSM在低频区域具有更强的近场辐射能力，其中WSM平板之间的耦合表面等离激元极化子起主导作用。通过将费米能级从0.01 eV连续调至0.15 eV，在T = 300 K时可获得高达58.5的大调制对比度，而在低温间隔[50,160] K中，对于20 nm的真空间隙，最小调制对比度可能会超过198。获得的结果可能有助于设计具有巨大调制对比度的基于WSM的热调制器。