  We propose an RKKY-type interaction that is mediated by a spin liquid. If a
spin liquid ground state exists such an interaction could leave a fingerprint
by ordering underlying localized moments such as nuclear spins. This
interaction has a unique phenomenology that is distinct from the RKKY
interaction found in fermionic systems; most notably the lack of a Fermi
surface and absence of the requirement for itinerant electrons, since most spin
liquids are insulators. As a working example we investigate the two-dimensional
spin-1/2 kagome antiferromagnet (KAFM), although the treatment remains general
and can be extended to other spin liquids and dimensions. We find that several
different nuclear spin orderings minimize the RKKY-type energy induced by the
KAFM but are unstable due to a zero-energy flat magnon band. Despite this we
show that a small magnetic field is able to gap out this magnon spectrum for
some of the orderings resulting in an intricate nuclear magnetism.
