Superconductivity of 2.2K under Pressure in Helimagnet CrAs

We report resistivity measurements of the helimagnet CrAs under pressures. The helimagnetic transition with T-N similar to 265 K at ambient pressure is completely suppressed above a critical pressure of P-c similar to 0.7 GPa, and super-conductivity is observed at similar to 2.2K for zero resistance, which exists in a wide pressure range extending beyond 3 GPa. Both the upper critical field H-c2 and the coefficient A in the resistivity increase toward P-c, suggesting that the superconductivity of CrAs is mediated by electronic correlations enhanced in the vicinity of the helimagnetic phase.