论文标题
利用Aharonov-bohm振荡探测石墨烯中可调式PN缝线中的klein隧道
Exploiting Aharonov-Bohm oscillations to probe Klein tunneling in tunable pn-junctions in graphene
论文作者
论文摘要
石墨烯的独特特征之一是，其电荷载体的费米波长可以在较大范围内进行静电调节。这原则上可以调整PN结的透明度，因为这取决于结与电源波长的物理延伸之间的比率，即在连接处的有效宽度上。但是，这个简单的想法 - 可以使Veselago镜头和Klein -Collimimator之间的平稳切换 - 由于大多数设置中可用的独立可算力的参数有限，因此很难在实验上进行实验证明。在这项工作中，我们介绍了一臂中带门可调节的PN可调式缝线的准焊接aharonov-bohm石墨烯环中的传输测量结果，并表明干扰模式提供了有关Klein隧道效率的明确信息，并在连接效率上有效宽度。我们发现PN界面的栅极控制透明度范围为35-100％。我们的结果与半经典描述非常吻合。
One of the unique features of graphene is that the Fermi wavelength of its charge carriers can be tuned electrostatically over a wide range. This allows in principle to tune the transparency of a pn-junction electrostatically, as this depends on the ratio between the physical extension of the junction and the electron wavelength, i.e. on the effective width of the junction itself. However, this simple idea - which would allow to switch smoothly between a Veselago lens and a Klein-collimator - has proved to be difficult to demonstrate experimentally because of the limited amount of independently-tunable parameters available in most setups. In this work, we present transport measurements in a quasi-ballistic Aharonov-Bohm graphene ring with gate tunable pn-junctions in one arm, and show that the interference patterns provide unambiguous information on the Klein tunneling efficiency and on the junctions effective width. We find a gate-controlled transparency of the pn-junctions ranging from 35-100%. Our results are in excellent agreement with a semiclassical description.
