Elbert E. M. Chia

Light hits a thin film, and an electric current instantly appears in it. This is how a pair of two materials works: molybdenum disulfide and cobalt. The first is a semiconductor, the second is a magnet. Between them, as it turns out, an invisible intermediary layer is born.

Usually, to generate terahertz waves (light between microwaves and infrared), researchers build a sandwich of different metals. One layer acts as the source, another as the receiver of charges. In such designs, platinum was assigned the role of a simple conductor. But it turns out it can work alone.

A copper crystal is squeezed in diamond anvil cells. As pressure mounts, a battle unfolds inside the material between two states: one prepares electrons for superconductivity, the other hinders their pairing. Scientists tracked this struggle using ultrashort laser pulses.