Department of Physics , Duke University , Durham , North Carolina 27708 , United States.
Department of Physics and Astronomy , Appalachian State University , Boone , North Carolina 28607 , United States.
Nano Lett. 2019 Feb 13;19(2):1039-1043. doi: 10.1021/acs.nanolett.8b04330. Epub 2019 Jan 14.
We investigate the electronic properties of ballistic planar Josephson junctions with multiple superconducting terminals. Our devices consist of monolayer graphene encapsulated in boron nitride with molybdenum-rhenium contacts. Resistance measurements yield multiple resonant features, which are attributed to supercurrent flow among adjacent and nonadjacent Josephson junctions. In particular, we find that superconducting and dissipative currents coexist within the same region of graphene. We show that the presence of dissipative currents primarily results in electron heating and estimate the associated temperature rise. We find that the electrons in encapsulated graphene are efficiently cooled through the electron-phonon coupling.
我们研究了具有多个超导终端的弹道平面约瑟夫森结的电子特性。我们的器件由单层石墨烯封装在氮化硼中，并具有钼铼接触。电阻测量得到了多个共振特征，这些特征归因于相邻和非相邻约瑟夫森结之间的超导电流。特别是，我们发现超导电流和耗散电流在石墨烯的同一区域共存。我们表明，耗散电流的存在主要导致电子加热，并估计相关的温升。我们发现封装在石墨烯中的电子通过电子-声子耦合得到有效冷却。
