Electron-Hole Doping Asymmetry of Superconductivity in a Strain-Tuned Organic Mott Transistor

Yoshitaka Kawasugi : The electron correlation in solids, or the Mott physics, offers intriguing phenomena in materials such as unconventional superconductivity. The key parameters for controlling the Mott physics are the electronic band filling and bandwidth. However, the simultaneous control of these parameters has been lacking so far, leaving a comprehensive phase diagram of correlated materials inaccessible. By combining electrostatic doping and bending-strain techniques, we are able to control the band filling and bandwidth of an organic Mott insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl in a single sample. As a result, doping-asymmetric ambipolar superconductivity has been observed in the proximity of the Mott transition.