Superconductivity above 120 kelvin in potassium-doped <i>p</i>-terphenyl

Exploring high temperature superconductors is the main direction of the superconducting field for more than 100 years. Recently, we observed superconductivity at 123 K at ambient pressure in potassium-doped p-terphenyl, a chain link organic molecule. Through a large number of experiments, we find that there are four superconducting phases with the critical temperatures of 4.3 K, 7.2 K, 43 K and 123 K in different samples, respectively. Interestingly, there is an aging effect for these superconducting phases. Raman spectra show the formation of the bipolarons during doping. The doping effects are examined by comparing with early X-ray diffraction and Raman spectra. Undoubtedly, all of these results open up a new visual field to discover more high temperature superconductors in organic molecules.