Youichi Yanase

When cooled strongly, a uranium-telluride crystal stops resisting current. Before that happens, at a slightly higher temperature, its resistance can still be measured — and it tells about the shape of the invisible paths along which electrons run.

An ordinary diode in electronics works like a one-way street: current flows in only one direction. In superconductors, where electricity flows without resistance, such behavior has long been elusive — current is usually symmetric. The authors of the new work found a way to create a perfect superconducting diode using light.

Imagine a postal service where couriers suddenly stop moving. It would seem that letters would stop arriving and communication between cities would break down. But what if the envelopes themselves suddenly gained the ability to change shape and transmit messages through a shared web without moving an inch?