论文标题
强烈抑制扭曲的双层石墨烯之间的近场热传输
Strong suppression of near-field thermal transport between twisted bilayer graphene near the magic angle
论文作者
论文摘要
扭曲的双层石墨烯（TBLG）最近成为研究各种外来运输现象的多功能平台。在这里，我们介绍了悬浮TBLG之间近场热辐射的理论研究，重点是魔术角。在手性对称的连续体模型中，由于降低的drude重量，我们在接近魔术角时观察到抑制的热流，在较低的温度和较大的间隙尺寸下抑制更大。当化学势位于电荷中性点附近的能量隙中时，在扭曲的0.25°内，可以在50 K处实现超过100倍的热流变化。通过降低电子散射速率，魔术角附近的辐射光谱大大缩小，导致超过10,000倍的抑制。此外，简短地考虑了支持的TBLG来促进实验测量。使用理性量身定制的底物，热流对比仍可以超过1000。我们还通过层间耦合能来讨论晶格松弛效果，发现更强的耦合会导致较小的热流对比度和更杰出的多摩德运输。我们的结果突出了魔术角TBLG在热传输中的巨大潜力，尤其是用于控制热辐射。
Twisted bilayer graphene (TBLG) has recently emerged as a versatile platform for studying a variety of exotic transport phenomena. Here, we present a theoretical study of near-field thermal radiation between suspended TBLG with a focus on the magic angle. Within the chirally symmetric continuum model, we observe a suppressed heat flow when approaching the magic angle owing to a reduced Drude weight, with greater suppressions at lower temperatures and larger gap sizes. When the chemical potential lies in the energy gap near the charge neutrality point, more than 100-fold heat-flow variation can be achieved at 50 K within 0.25°of twist. By reducing the electron scattering rate, the radiation spectrum near the magic angle dramatically narrows, leading to over 10,000-fold of suppression. In addition, supported TBLG is briefly considered to facilitate experimental measurement. With rationally tailored substrates, the heat-flow contrast can still exceed 1000. We also discuss lattice relaxation effect in terms of the interlayer coupling energy, finding that a stronger coupling leads to a smaller heat-flow contrast and more prominent multiband transport. Our results highlight the great potential of magic-angle TBLG in thermal transport, especially for controlling thermal radiation.
