Low Energy Excitations in Low Carrier Concentration System of CeSb and Yb-Monopnictides

Abstract

The dHvA effect has been measured in several heavy Fermion substances. There are some discrepancies between the observed cyclotron mass and the mass estimated from the linear term of low temperature specific heat. A typical example is CeB₆ in which the cyclotron mass in lower magnetic field observed by Onuki et al (1) is twice smaller than that estimated from γ. We believed that this discrepancy is due to unobservable Fermi Surfaces with a much heavier cyclotron mass at that time. CeSn₃ is taken as a typical example which exhibits a good agreement between the band calculated mass(2) and dHvA effect one(3). In this compound, theoretical prediction of mass enhancement factor in the specific heat is about 4, while the ratio of band mass and observed cyclotron mass is 4 only along special direction of the Fermi surface and is nearly 2–3 along other all direction. The discrepancy is clear and may be due to the error in both experimental and theoretical estimations.