Imaging Viscous Flow of the Dirac Fluid in Graphene

July 23, 2020
Imaging Viscous Flow of the Dirac Fluid in Graphene

It sounds like pure sorcery: using diamonds to observe invisible power swirling and flowing through carefully crafted channels. But these diamonds are a reality. [Harvard Physics Associate Mark J. H. Ku, and postdoc Tony Zhou, together with other members of Prof. Amir Yacoby's group, JQI Fellow Ronald Walsworth, and colleagues from several other institutions], have developed a way to use diamonds to see the elusive details of electrical currents.

The new technique gives researchers a map of the intricate movement of electricity in the microscopic world. The team demonstrated the potential of the technique by revealing the unusual electrical currents that flow in graphene, a layer of carbon just one atom thick. Graphene has exceptional electrical properties, and the technique could help researchers better understand graphene and other materials and find new uses for them.

In a paper published on July 22 in the journal Nature, the team describes how their diamond-based quantum sensors produce images of currents in graphene. Their results revealed, for the first time, details about how room-temperature graphene can produce electrical currents that flow more like water through pipes than electricity through ordinary wires. "Understanding strongly interacting quantum systems, like the currents in our graphene experiment, is a central topic in condensed matter physics," says Ku, the lead author of the paper. "In particular, collective behaviors of electrons resembling those of fluids with friction might provide a key to explaining some of the puzzling properties of high-temperature superconductors."

Continue reading the press release on EurikAlert: "Diamonds Shine a Light on Hidden Currents in Graphene." Read also the research paper: Mark J. H. Ku, Tony X. Zhou, Qing Li, Young J. Shin, [et al.], " Imaging viscous flow of the Dirac fluid in graphene," Nature 583, 537–541 (2020).