Muon spin relaxation studies in strongly correlated electron systems

We describe recent progress of muon spin relaxation (μSR) studies in heavy-fermion (HF) and other strongly correlated electron systems. Measurements of the magnetic field penetration depth λ in HF superconductors UPt3, URu2Si2, UPd2Al3 and U2PtC2 have revealed that these systems are characterized by large ratios Tc/TF = 0.1−0.01 of Tc vs Fermi temperature TF derived from λ. This feature is common to high-Tc cuprate and other exotic …