Kondo insulator: P-wave bose condensate of excitons

In the Anderson lattice model for a mixed-valent system, the d-f hybridization can possess a p-wave symmetry. The strongly correlated insulating phase in the mean-field approximation is shown to be a p-wave Bose condensate of excitons with a spontaneous lattice deformation. We study the equilibrium and linear response properties across the insulator-metal transition. Our theory supports the empirical correlation between the :lattice deformation and the magnetic susceptibility and predicts measurable ultrasonic and high-frequency phonon behavior in mixed-valent semiconductors.