We use the lattice Anderson model on a small cluster to calculate the effect of an external magnetic field on the specific heat of a heavy-fermion system. The suppression of the specific heat results from the spreading of a manifold that contains states of different spins through the Zeeman effect. Our results are compared qualitatively with experiments on ${\mathrm{CeCu}}_6$.

• Received 22 May 1992

DOI:https://doi.org/10.1103/PhysRevB.47.2890