  Light clusters (mass number $A \leq 4$) in nuclear matter at subsaturation
densities are described using a quantum statistical approach. In addition to
self-energy and Pauli-blocking, effects of continuum correlations are taken
into account to calculate the quasiparticle properties and abundances of light
elements. Medium-modified quasiparticle properties are important ingredients to
derive a nuclear matter equation of state applicable in the entire region of
warm dense matter below saturation density. The influence of the
nucleon-nucleon interaction on the quasiparticle shift is discussed.
