Superconductivity and spin gap in the spin-ladder cuprate, Sr2Ca12Cu24O41Sr2Ca12Cu24O41

Pressure-induced superconductivity in a spin-ladder cuprate Sr2Ca12Cu24O41Sr2Ca12Cu24O41 was investigated on the microscopic level by using 6363Cu nuclear magnetic resonance (NMR) under pressure of 3.5 GPa. We observed both spin and superconducting gaps in separated temperature regions. We found that the superconducting state possesses a full gap and is quite stable even at high fields close to the conventional Pauli limit.