Fermi surface of the periodic Anderson model detected by momentum-resolved charge compressibility

We investigate a Fermi surface of the periodic Anderson model by the finite temperature quantum Monte Carlo method. Although the Luttinger sum rule predicts the system has a large Fermi surface (at T=0) that contains both conduction and f electrons, the momentum distribution function n(k) at a finite temperature shows large change at a small Fermi surface that contains only conduction electrons without f electrons. Also clear signature of the large Fermi surface is not easily observed. On the other hand, the momentum-resolved compressibility dn(k)/dμ, which reflects effects of an infinitesimal doping, shows a peak structure at the large Fermi surface even at an easily accessible temperature