Visualizing superconductive coupling over atomic steps

Researchers at the International Center for Materials Nanoarchitectonics, Tsukuba, together with scientists across Japan, have uncovered the underlying structures and the behavior of currents on the surface of Si(111)-(√7 x √3)which provide clues to its superconductivity. Superconductors have effectively zero resistance and act as perpetual carriers of electric current with no need for a connected power source. As such they have many applications in electronics. One of the thinnest two-dimensional materials ever created, called Si(111)-(the square root of 7 x the square root or 3)-In - individual indium metal atoms added to a silicon surface - recently surprised scientists with its superconducting abilities. The race is now on to find out how and why this silicon surface is capable of superconductivity, as well as what uses it may have. Takashi Uchihashi and co-workers at the International Center for Materials Nanoarchitectonics, Tsukuba, together with scientists across Japan, have now uncovered the underlying structures and the behavior of currents on the surface of Si(111)-(the square root of 7 x the square root of 3)-In which provide clues to its superconductivity. The silicon surface comprises individual terraces separated by steps measuring the height of a single atom (‘atomic steps’). These steps could potentially interrupt, or decouple, neighboring terraces an...