  Correlated interaction between dilute localized impurity electrons with the
itinerant host conduction electrons in metals gives rise to the conventional
many-body Kondo effect below sufficiently low temperature. In sharp contrast to
these conventional Kondo systems, we report an intrinsic, robust and
high-temperature Kondo state in two-dimensional semiconducting phosphorene.
While absorbed at a thermodynamically stable lattice defect, Cr impurity
triggers an electronic phase transition in phosphorene to provide conduction
electrons, which strongly interact with the localized moment generated at the
Cr site. These manifests into intrinsic Kondo state, where the impurity moment
is quenched at multi-stage and at temperatures in the 40-200 K range. Further,
along with a much smaller extension of Kondo cloud, the predicted Kondo state
is shown to be robust under uniaxial strain and layer thickness, which greatly
simplifies its future experimental realization. We predict the present study
will open up new avenues in Kondo physics and trigger further theoretical and
experimental studies.
