Hydrogen-rich superconductors at high pressures

The hydrogen-rich superconductors stabilized at high-pressure conditions have been the subject of topic interests. There is an essential hope that hydrogen-rich superconductors are promising candidates of room-temperature superconductors. Recent advances in first-principles crystal structure prediction techniques have opened up the possibility of reliable prediction of superconductive structures, and subsequent superconductivity calculations based on phonon-mediated superconducting mechanism revealed a general appearance of high temperature superconductivity in pressurized hydrides. Theory-orientated experiments at high pressure discovered a number of hydrogen-rich superconductors, among which sulfur hydrides exhibit a remarkably high superconducting critical temperature reaching 203K. In this review, we discuss the emerging research activities towards hydrogen-rich superconductors at high pressures and outlook the future direction in the field. (C) 2017 Wiley Periodicals, Inc.