论文标题
石墨烯中声音和热传输的张力调整
Tension tuning of sound and heat transport in graphene
论文作者
论文摘要
在2D材料中，声音传输的热传输与3D晶体中的热传输根本不同，因为平面外的声子以一种独特的方式强烈依赖于张力和弯曲刚度的独特方式传播。由于平面内部和平面外声子浴是解耦的，因此初步研究表明，它们为2D材料提供了独立的热传输和存储途径。在这里，我们通过静电力诱导独立的石墨烯膜张力，并使用光力学技术证明它可以将热传输速率更改高达33％。使用弹道Debye模型，我们说明了这些观察结果，并提取了弯曲声音子的平均弯曲刚度，与在散装结构中看到的立方依赖性相反，它与膜的面积质量密度近似线性增加。因此，我们不仅阐明了悬浮的2D材料中的语音热传输机制，而且还提供了一种有前途的途径来控制纳米级的热传输。
Heat transport by acoustic phonons in 2D materials is fundamentally different from that in 3D crystals because the out-of-plane phonons propagate in a unique way that strongly depends on tension and bending rigidity. Since in-plane and out-of-plane phonon baths are decoupled, initial studies suggested they provide independent pathways for heat transport and storage in 2D materials. Here, we induce tension in freestanding graphene membranes by electrostatic force, and use optomechanical techniques to demonstrate that it can change the rate of heat transport by as much as 33%. Using a ballistic Debye model, we account for these observations and extract the average bending rigidity of the flexural acoustic phonons, which increases approximately linearly with the membrane's areal mass density, in contrast to the cubic dependence seen in bulk structures. Thus, we not only elucidate phononic heat transport mechanisms in suspended 2D materials, but also provide a promising route for controlling nanoscale heat transport by tension.
