The search for new superconducting compounds with higher critical temperatures Tc's has long been the very heart of scientific research in modern condensed matter physics, materials science, and chemistry. It took 75 years for scientists to push the Tc above liquid nitrogen boiling temperaturesince the discovery of superconductivity. So far, the record high Tc 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 Tc of around 200 K at high pressure of about 150 GPa. While keeping these records for superconductivity, either the toxicityof these superconductors or the requirement of extreme pressure condition for superconductivity limits their technology applications. Here I will talk about our recent discovery of high-Tc superconductivity in polyparaphenylene oligomers. I will show that doping achain link molecule – p-terphenyl by potassium can bring about superconductivity at 123 K at atmosphere pressure, which is comparable to the highest Tc in cuprates. Superconductivity have also been found in other compounds of oligomers. The easy processability, light weight, durability of plastics, and environmental friendliness of this kind of these new superconductors 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.
This work is in collaboration with Ren-Shu Wang, Kai Zhang, Dong-Yu Yang, Jia-Feng Yan, Liu-Cheng Chen, Zi-Yu Zhao, Yun Gao, Zhong-Bing Huang, Guo-Hua Zhong, Chao Zhang, and Hai-Qing Lin.