Origin of unusually large T-c enhancement in PrBa2Cu3Oy under pressure

The recently discovered PrBa2Cu3Oy superconductor possesses remarkable prop erties. The superconducting transition temperature T-c has been found to ex ceed 100 K under a pressure over 8 GPa and still have a pontential increase . We show that the extended t-J model with d-wave pairing for high-T-c supe rconductivity can explain the unusual pressure dependence of T-c in PrBa2Cu 3Oy by taking into account the variations of the hole concentration in the CuO2 planes and the effective interaction with pressure. We suggest further experiments to enhance T-c at ambient pressure in PrBa2Cu3Oy.