二氧化硅表面间的极端近场热传递
Extreme near-field heat transfer between silica surfaces
AI总结：
本研究通过NEMD模拟探究亚纳米级间隙下二氧化硅表面的极端近场热传递，验证了传热系数与距离的平方反比关系，分析了与涨落电动力学理论的偏差成因。
摘要：
尽管近期实验显示，间隙尺寸约为10 nm的平行平面二氧化硅表面之间的辐射热通量有显著提升，但亚纳米级间隙距离的相关研究仍属空白。本研究采用非平衡分子动力学（non-equilibrium molecular dynamics, NEMD）模拟，探究了无定形和晶态两种形态的SiO₂平板之间的热传递特性。当间隙尺寸为2 nm时，我们发现传热系数较间隙尺寸为10 nm时的实验值大幅提升约30倍，证实了其与距离的关系符合涨落电动力学（fluctuational electrodynamics, FE）理论预测的平方反比关系。NEMD与FE的对比分析显示二者总体吻合良好，针对无定形二氧化硅的吻合度尤其突出。光谱热传递分析表明，间隙尺寸对热传递有显著影响，传热峰值对应介电函数的共振位置。在更小间隙尺寸下，结果与涨落电动力学理论的偏差可通过声子隧穿效应及表面附近的介电常数梯度效应加以解释。
英文摘要：
Despite recent experiments exhibiting an impressive enhancement in radiative heat flux between parallel planar silica surfaces with gap sizes of about 10 nm, the exploration of sub-nanometric gap distances remains unexplored. In this work, by employing non-equilibrium molecular dynamics (NEMD) simulations, we study the heat transfer between two SiO2 plates in both their amorphous and crystalline forms. When the gap size is 2 nm, we find that the heat transfer coefficient experiences a substantial ~30-fold increase compared to the experimental value at the gap size of 10 nm confirming the dependence on the distance inversely quadratic as predicted by the fluctuational electrodynamics (FE) theory. Comparative analysis between NEMD and FE reveals a generally good agreement, particularly for amorphous silica. Spectral heat transfer analysis demonstrates the profound influence of gap size on heat transfer, with peaks corresponding to the resonances of dielectric function. Deviations from fluctuational electrodynamics theory at smaller gap sizes are interpreted in the context of acoustic phonon tunneling and the effects of a gradient of permittivity close to the surfaces.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
