二维系统研究中的无电极输运方法  

Contactless transport method of two-dimensional electron system studies

作　　者：赵利利 吴蒙蒙 林文璐 刘阳 Zhao Li-Li;Wu Meng-Meng;Lin Wen-Lu;Liu Yang(International Center for Quantum Materials,School of Physics,Peking University,Beijing 100871,China)

机构地区：[1]北京大学物理学院,量子材料科学中心,北京100871

出　　处：《物理学报》2022年第12期238-243,共6页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2019YFA0308403);国家自然科学基金(批准号:92065104,12074010)资助的课题。

摘　　要：介绍了两种极低温环境下无接触电极输运的测量方法—电容测量和表面声波测量.两种方法通过高频电场与电子的相互作用来研究量子系统体态的物理特性.首先介绍了在极低温下通过高精度电容测量研究高质量二维电子气特性的初步结果.实验装置具备在10 mK—300 K,0—14 T环境中对小于1 pF的电容实现0.05%以上分辨率的能力.还介绍了利用表面声波研究二维电子系统的结果,可以在0.1 nW的输入激励下获得小于10;的灵敏度.这些测量手段在研究二维系统尤其是无法制作高质量接触电极的材料中具有广泛的应用前景.We introduce two contactless measurement methods at extremely low temperature:capacitances and surface acoustic waves.Both methods can be used to study the physical properties of the quantum system through the interaction between electrons and high frequency electric field.We first present preliminary results of high-mobility two-dimensional electron systems studied by a high-precision capacitance measurement method at extremely low temperature.Our setup can resolve<0.05%variation of a<1 pF capacitance at 10 mK–300 K and 0–14 T.Second,we also study two-dimensional electron systems using surface acoustic waves.We can use0.1 nW excitation and obtain<10–5 sensitivity.These measurement methods may be widely applied to the study of two-dimensional systems,especially the materials without high quality contacts.

关 键 词：二维电子气 量子霍尔效应 电容 表面声波 

分 类 号：O469[理学—凝聚态物理]