Xianhui Chen

Heat and electricity usually go hand in hand, but making heat turn into current is no easy task. The material GdTe3, a layered crystal with a metallic sheen, when cooled to 20 kelvins (that's −253 °C) and placed in a strong 13.5-tesla magnetic field, showed something unexpected: its ability to generate electricity from heat shot up by 1075%.

A ceramic plate as thin as a soap film, and through it flows current with zero resistance. That's the superconductivity achieved in nickelates, relatives of the famous cuprate superconductors. Previously, this required enormous pressure, comparable to that at the ocean floor.

A tiny sandwich of oxides, grown layer by layer, becomes perfectly conducting at about minus 200 degrees Celsius. This is not a magic trick but a new chapter in the search for high-temperature superconductors.