论文标题
来自半经典兰格文文分子动力学的单分子连接的温度依赖性热传输
Temperature-dependent thermal transport of single molecular junctions from semi-classical Langevin molecular dynamics
论文作者
论文摘要
最近，使用Picowatt分辨率扫描探针测量了在室温下单分子连接的导热电导率。但是，需要完全理解在单分子极限和单分子设备的开发的能量转移需要较宽的温度范围内的热传输。在这里，采用了半经典的兰格文分子动力学方法，分别对AU和石墨烯电极之间的烷烃链的热运输进行了比较研究。我们说明了两种类型的交界处的量子统计和非谐相互作用的不同作用。对于石墨烯连接处，量子统计在室温下是必不可少的，而非谐波相互作用可以忽略不计。对于AU交界处，这是另一种方式。我们的研究为理论上在整个温度范围内通过在一个理论框架内包括量子统计和肛门相互作用，从理论上理解现实的单分子连接的热运输铺平了道路。
Thermal conductance of single molecular junctions at room temperature has been measured recently using picowatt-resolution scanning probes. However, fully understanding thermal transport in a much wider temperature range is needed for the exploration of energy transfer at single-molecular limit and the development of single-molecular devices. Here, employing a semiclassical Langevin molecular dynamics method, a comparative study is performed on the thermal transport of an alkane chain between Au and graphene electrodes, respectively. We illustrate the different roles of quantum statistics and anharmonic interaction in the two types of junctions. For a graphene junction, quantum statistics is essential at room temperature, while the anharmonic interaction is negligible. For a Au junction, it is the other way. Our study paves the way for theoretically understanding thermal transport of realistic single-molecular junctions in the full temperature range by including both quantum statistics and anharmonic interaction within one theoretical framework.
