利用石墨烯等离激元与表面声子耦合增强量子摩擦  

Enhancement of quantum friction via coupling of surface phonon polariton and graphene plasmons

作　　者：张超杰[1] 周婷[1] 杜鑫鹏 王同标[1] 刘念华[2] 

机构地区：[1]南昌大学物理系,南昌330031 [2]南昌大学高等研究院,南昌330031

出　　处：《物理学报》2016年第23期215-222,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11264029;11264030);江西省自然科学基金(批准号:20151BAB202017)资助的课题~~

摘　　要：详细研究了以Si C为基底的石墨烯之间量子摩擦.由于Si C可以支持表面声子极化子,石墨烯可以支持表面等离激元,在一定的频率范围,表面声子极化子和等离激元能够耦合.发现相对于单纯石墨烯或Si C来说,由于表面声子极化子与石墨烯等离激元的共同作用,以Si C为基底的石墨烯之间的量子摩擦有很大的增强.此外,我们发现量子摩擦系数随石墨烯化学势的增加先增加后减小,摩擦系数可以取得最大值.本文的研究对于微/纳机电系统的制作具有积极的意义.In our daily life, frictions are very common when two bodies in direct contact relatively move. However, when two bodies are separated by a finite distance, due to the quantum fluctuations inside the bodies, they may still experience a friction when they relatively move. Such a phenomenon is often called quantum friction, which has been studied for more than a decade. It has shown in previous studies that the surface modes, such as surface phonon polaritions（SPh Ps）or surface plasmon polaritions（SPPs） have significant contribution to enhancing the quantum friction. However, to the best of our knowledge, the contribution of coupling from SPh Ps and SPPs to quantum friction is still unknown.Here, we report a detailed study on the quantum frictions between two graphene sheets with the silicon carbide（SiC）substrates. For comparison, the quantum frictions between two other samples, i.e., SiC/SiC and graphene/graphene are also studied. As indicated in previous studies, SPh Ps and SPPs, supported by SiC and graphene, respectively, can couple together in special frequency ranges. The coupling of SPh Ps and SPPs can be tuned by varying the chemical potential of graphene. The coupling modes shift toward higher frequency as the chemical potential increases. Firstly, we analyze qualitatively the effects of coupled surface modes on quantum friction with the help of dispersion relation. Secondly, we calculate the quantum friction coefficients numerically for the three different samples. We find that due to the coupling of SPh Ps and SPPs, the quantum friction between graphene sheets with SiC substrates is larger than that between the SiC or monolayer graphene sheets. We demonstrate that the coupling of SPh Ps and SPPs can be modulated by chemical potential of graphene; therefore, the relationship between quantum friction coefficient and chemical potential is also studied. We observe that with the increase of chemical potential, quantum friction coefficient follows a nonmonotonic trend, i.e., it first increases to i

关 键 词：量子摩擦 石墨烯 等离激元 

分 类 号：O413[理学—理论物理] O313.5[理学—物理]