Theory-directed discovery of high-temperature superconductivity in clathrate hydrides at high pressure

The search for room-temperature superconductivity has been one of the great challenges in condensed matter physics ever since the first observation of superconductivity with a critical temperature (Tc) of 4 K in mercury in 1911. Recent years have been witness to the successful observation of superconductivity in highly compressed SH3 (Tc = 203 K at 155 GPa) and classes of clathrate hydrides (e.g., CaH6, YH6, YH9, and LaH10) with LaH10 holding a record high Tc of 250-260 K at ~180 GPa among these binary hydrides. Each of these experimental studies was guided by theoretical predictions. New experimental work on the Ca-H system has finally confirmed the theoretical calculation that launched this effort, the 2012 prediction of a high-Tc superconductivity in CaH6 above 200 K.