  Motivated by recent experimental interest in tunneling into heavy electron
materials, we present a theory for electron tunneling into a Kondo lattice. The
passage of an electron into the Kondo lattice is accompanied by a simultaneous
spin flip of the localized moments via cotunneling mechanism. We compute the
tunneling current with the large-$N$ mean field theory. In the absence of
disorder, differential tunneling conductance exhibits two peaks separated by
the hybridization gap. Disorder effects lead to the smearing of the gap
resulting in a Fano lineshape.
