品质因子可调的石墨烯纳米机械振子  

Graphene Nanomechanical Resonator with Tunable Quality Factor

作　　者：苏子佳 SU Zijia(CAS Key Laboratory of Quantum Information,University of Scienceand Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学,中国科学院量子信息重点实验室,合肥230026

出　　处：《低温物理学报》2020年第4期192-198,共7页Low Temperature Physical Letters

摘　　要：纳米机械振子尺寸小,质量轻,可以用来制作探测力、质量等微小物理量的超灵敏探测器.石墨烯拥有质量轻、密度低和杨氏模量高等特性,被认为是制作纳米机械振子的理想材料.石墨烯纳米机械振子因其具有的谐振频率高、品质因子高和谐振频率可调性高等优势,近年来得到了人们的广泛关注.作为表征纳米机械振子性能的一个重要指标,品质因子越高,意味着纳米机械振子耗散越低,纳米机械振子的灵敏度越高.本文通过微纳加工的工艺制备出一种谐振频率随栅压可调(调节的范围为73 MHz~90 MHz)的石墨烯纳米机械振子样品,研究其在极低温高真空环境下的品质因子与栅极电压之间的关系.实验表明通过栅压调节振子的内部应力,能够使石墨烯纳米机械振子品质因子从220提高到1000.我们的结果为二维材料纳米机械振子的耗散研究提供了一种新的研究思路.Nanomechanical resonators are small in size and light in weight,and can be used for ultra-sensitive force and mass detection.Graphene has the characteristics of light weight,low density and high Young’s modulus,and is considered to be an ideal material for fabricating nanomechanical resonators.Graphene nanomechanical resonators have received extensive attentions in recent years because of their advantages such as high resonant frequency,high quality factor and high tunability of the resonant frequency.As an important parameter to characterize the performance of nanomechanical resonators,the higher the quality factor,the lower the dissipation,leading to a higher sensitivity of the nanomechanical resonators.Here,we fabricate a doubly-clamped graphene nanomechanical resonator with a resonance frequency that can be tuned by the gate voltage(from 73 MHz to 90 MHz).The relationship between its quality factor and the gate voltage under low temperature and high vacuum environment is studied.The experimental result shows that applying external stress to the resonator by gate voltage can increase the quality factor from 220 to 1000.Our results shed light on the study of the dissipation of the two-dimensional material based nanomechanical resonators.

关 键 词：石墨烯 纳米机械振子 耗散 品质因子 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TQ127.11[化学工程—无机化工]