Superconductivity above 120 kelvin in a chain link molecule

Abstract

The search for new superconducting compounds with higher critical temperatures $T_{c}^{\prime}$s has long been the very heart of scientific research on superconductivity. It took 75 years for scientists to push the $T_{c}$ above liquid nitrogen boiling temperature since the discovery of superconductivity. So far, the record high $T_{c}$ of about 130 K at atmosphere pressure was reported in some multilayer Hg(Tl)-Ba-Ca-Cu-O compounds. Meanwhile, sulfur hydride system holds the highest $T_{c}$ of around 200 K at high pressure of about 150 GPa. While keeping these records for superconductivity, either the toxicity of these superconductors or the requirement of extreme pressure condition for superconductivity limits their technology applications. Here we show that doping a chain link molecule $-$ $p$-terphenyl by potassium can bring about superconductivity at 123 K at atmosphere pressure, which is comparable to the highest $T_{c}$ in cuprates. The easy processability, light weight, durability of plastics, and environmental friendliness of this kind of new superconductor have great potential for the fine-tuning of electrical properties. This study opens a window for exploring high temperature superconductivity in chain link organic molecules.