Phase-coherent transport in graphene quantum billiards
Phase-coherent transport in graphene quantum billiards
复制标题
DOI：
10.1126/science.1144359
复制
发表时间：
2007-09-14
期刊：
影响因子：
56.9
通讯作者：
Lau, C. N.
中科院分区：
文献类型：
--
作者：
Miao, F.;Wijeratne, S.;Lau, C. N.
石墨烯作为一种新兴的电子材料和凝聚态物理模型系统，其电输运特性已成为人们关注的热点。通过对单层和双层石墨烯进行低温输运光谱分析，我们观察到正常电极的多次电荷反射波和超导电极的多次安德烈夫反射波的弹道传播和量子干涉，从而实现了仅在边界处散射的量子台球。与传统二维材料的导电性相比，石墨烯在狄拉克点的导电性是几何相关的，因为它是通过消失模式传导的，只有在短和宽的器件中才接近理论值4e(2)/pi h（其中e是电子电荷，h是普朗克常数）。这些独特的输运性质对理解混沌量子系统和实现纳米电子器件（如弹道晶体管）具有重要意义。
As an emergent electronic material and model system for condensed-matter physics, graphene and its electrical transport properties have become a subject of intense focus. By performing low-temperature transport spectroscopy on single-layer and bilayer graphene, we observe ballistic propagation and quantum interference of multiply reflected waves of charges from normal electrodes and multiple Andreev reflections from superconducting electrodes, thereby realizing quantum billiards in which scattering only occurs at the boundaries. In contrast to the conductivity of conventional two-dimensional materials, graphene's conductivity at the Dirac point is geometry-dependent because of conduction via evanescent modes, approaching the theoretical value 4e(2)/pi h (where e is the electron charge and h is Planck's constant) only for short and wide devices. These distinctive transport properties have important implications for understanding chaotic quantum systems and implementing nanoelectronic devices, such as ballistic transistors.