Shanghai Jiao Tong University Discovers Superconductivity in Single-Crystalline Graphene
TapTechNews June 20 news, TapTechNews learned from the official WeChat public account of Shanghai Jiao Tong University that the research team of Shanghai Jiao Tong University observed superconductivity in the case of electron doping in single-crystalline graphene for the first time, and the relevant results were published in Nature.
Paper address: https://www.nature.com/articles/s41586-024-07584-w
The superconductivity, a macroscopic quantum phenomenon, was first observed by the Dutch scientist H.K. Onnes when studying the electrical transport properties of mercury at low temperatures in 1911 and is one of the milestone discoveries in condensed matter physics.
This research of Shanghai Jiao Tong University is of great significance for understanding the superconductivity mechanism of crystalline graphene and twisted graphene systems, and for designing and fabricating high-quality new superconducting quantum devices based on graphene systems.
The experimental team successfully fabricated a high-quality bilayer graphene and tungsten diselenide heterojunction sample, enabling the application of a vertical displacement electric field of up to 1.6 V/nm.
By carrying out a systematic cryogenic quantum transport measurement, combined with electric field regulation and electrostatic doping regulation, the experimental team revealed the complete phase diagram of the hole-doped superconductivity with the change of the displacement electric field and the carrier concentration.
The experimental team observed the superconducting state in the case of electron doping, which is the first observation of superconductivity with electron doping in single-crystalline graphene.
The strength of the superconducting state at both the hole and electron ends can be effectively adjusted by the applied vertical displacement electric field. The highest superconducting transition temperatures measured experimentally are about 450 mK and 300 mK respectively, which is also the highest record of the superconducting transition temperature observed in single-crystalline graphene system so far.