Heavy quasiparticles in CeCu₆studied using magnetic quantum oscillations

Abstract

Angle resolved measurements of the de Haas-van Alphen effect are reported in the heavy-fermion compound CeCu6. The experiments confirm the presence at low temperature of a sharply defined Fermi surface resulting from the existence of heavy long-lived charged fermion quasiparticles. LMTO electronic structure calculations have been performed within the local density approximation, in which the f electrons are included as either band or core states, but in neither case are the results in satisfactory agreement with experiment. The measured effective masses, which are in the range 6-80 me, are found to be magnetic field dependent in a manner which closely resembles that of the linear specific heat coefficient. The authors deduce that, in zero applied field, the mass renormalization in CeCu6 is greater than 200.