Andreev spectroscopy on the filled skutterudite superconductor PrOs4Sb12

We present Andreev spectroscopy data, down to 80 mK and up to 2.5 T, taken with ballistic point contacts on single crystals of the heavy-fermion superconductor PrOs4Sb12. Spectral dependences on magnetic field H and temperature T were studied to track how the order-parameter symmetry evolves and thus map out the H-T phase diagram. We observe a field-driven change in the nodality of the order-parameter suggesting that there are multiple superconducting phases, with different pairing symmetries, in PrOs4Sb12.