High-field investigation on 4f-5d exchange interaction in phyrochlore irridates

The newly suggested 4f-5d exchange interaction is investigated in plyrochore irridates, Nd2Ir2O7 and Sm2Ir2O7. The LF dependence of muon-spin relaxation rate up to 5 T is measured in order to clarify the peak of the spectrum densify of the spin fluctuation of Nd and Sm in the magnetically ordered state of Ir spins. We aim to prove the existence of the 4f-5d exchange interaction between Nd/Sm and Ir spins. We also try to clarify the emergence of the quantum spin fluctuation and the magnetically ordered state of Ir spins via investigating the spin fluctuation of Nd and Sm.