Exotic heavy-fermion state in the filled skutteruditePrFe4P12uncovered by the de Haas–van Alphen effect

Abstract

We report the de Haas–van Alphen (dHvA) experiment on the filled skutterudite ${\mathrm{PrFe}}_4{\mathrm{P}}_{12}$ exhibiting apparent Kondo-like behaviors in the transport and thermal properties. We have found enormously enhanced cyclotron effective mass $m_{\mathrm{c}}^{*}=81\mathrm{}{m}_0$ in the high field phase, which indicates that ${\mathrm{PrFe}}_4{\mathrm{P}}_{12}$ is the first Pr compound in which really heavy mass has been unambiguously confirmed. Also in the low field nonmagnetic ordered phase (LOP), we observed the dHvA branch with $m_{\mathrm{c}}^{*}=10\mathrm{}{m}_0$ that is quite heavy taking into account its small Fermi surface volume (0.15% of the Brillouin zone size). The insensitivity of mass in LOP against the magnetic field suggests that the quadrupolar interaction plays a main role both in the mass renormalization and the LOP formation.