  The delicate balance of spin-screening and spin-aligning interactions
determines many of the peculiar properties of dilute magnetic systems. We study
a surface-supported all-organic multi-impurity Kondo spin system at the atomic
scale by low-temperature scanning tunnelling microscopy and -spectroscopy. The
model system consists of spin-1/2 radicals that are aligned in one-dimensional
chains and interact via a ferromagnetic RKKY interaction mediated by the 2DEG
of the supporting substrate. Due to the RKKY-induced enhanced depopulation of
one spin-subband in the 2DEG, we finally succeeded to detect the so far
unobserved 'Kondo state' as opposed to the well-established Kondo resonance.
Its cloud of screening electrons, that are virtually bound to the radicals
below the Kondo temperature, represents the extended exchange hole of the
ferromagnetically polarized spin chain imaged here in real space.
