Abstract Due to the weak van der Waals interaction between two-dimensional materials, one can stack or twist two-dimensional materials to obtain novel or enhanced physical and chemical properties. In this study, the relationship between twist angle and friction properties of bilayer graphene and MoS2/MoSe2 van der Waals heterostructures was studied using molecular dynamics simulations by considering the effects of temperature, relative velocity, slip direction and normal force. The results show that for twisted bilayer graphene, the friction force reduced significantly in incommensurate stacking, and the superlubricity (μ ≤ 0.001) happens. For MoS2/MoSe2 heterostructures, the superlubricity is achieved in the range of twist angles of 9° ≤ θ ≤ 51°. In both systems, the friction force increases with the increase of temperature, and increases linearly with increasing of normal force and relative velocity. And in the range of the twist angle close to aligned commensurate contact (θ ≤ 10° and θ ≥ 50°), the friction force changes more significantly. After a certain angle of rotation (under misaligned incommensurate state), the anisotropy of friction degenerated remarkably, which is two orders of magnitude lower than that of commensurate stacking. These results deepen the understanding of superlubricity in two-dimensional materials, and will also shed light on the applications of two-dimensional materials.

中文翻译：

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双层石墨烯和 MoS2/MoSe2 范德华异质结构中的层间摩擦和超润滑性

摘要 由于二维材料之间较弱的范德华相互作用，人们可以通过堆叠或扭曲二维材料来获得新的或增强的物理和化学性质。在这项研究中，通过考虑温度、相对速度、滑移方向和法向力的影响，使用分子动力学模拟研究了双层石墨烯和 MoS2/MoSe2 范德华异质结构的扭曲角和摩擦性能之间的关系。结果表明，对于扭曲的双层石墨烯，在不相称的堆叠中摩擦力显着降低，并发生超润滑性（μ ≤ 0.001）。对于 MoS2/MoSe2 异质结构，在 9° ≤ θ ≤ 51° 的扭曲角范围内实现了超润滑性。在两个系统中，摩擦力都随着温度的升高而增加，并且随着法向力和相对速度的增加而线性增加。并且在接近对齐等比接触的扭转角范围内（θ≤10°和θ≥50°），摩擦力变化更显着。旋转一定角度后（在未对准不公度状态下），摩擦各向异性显着退化，比相称堆叠低两个数量级。这些结果加深了对二维材料超润滑性的理解，也将为二维材料的应用提供启示。摩擦各向异性显着退化，比相称堆积低两个数量级。这些结果加深了对二维材料超润滑性的理解，也将为二维材料的应用提供启示。摩擦各向异性显着退化，比相称堆积低两个数量级。这些结果加深了对二维材料超润滑性的理解，也将为二维材料的应用提供启示。