  The ground state and low energy excitations of the SU(m|n) supersymmetric
Haldane-Shastry spin chain are analyzed. In the thermodynamic limit, it is
found that the ground state degeneracy is finite only for the SU(m|0) and
SU(m|1) spin chains, while the dispersion relation for the low energy and low
momentum excitations is linear for all values of m and n. We show that the low
energy excitations of the SU(m|1) spin chain are described by a conformal field
theory of m non-interacting Dirac fermions which have only positive energies;
the central charge of this theory is m/2. Finally, for n \ge 1, the partition
functions of the SU(m|n) Haldane-Shastry spin chain and the SU(m|n)
Polychronakos spin chain are shown to be related in a simple way in the
thermodynamic limit at low temperatures.
