  Ba3Mn2O8 is a spin-dimer compound based on pairs of S = 1, 3d2, Mn5+ ions
arranged on a triangular lattice. Antiferromagnetic intradimer exchange leads
to a singlet ground state in zero-field, with excited triplet and quintuplet
states at higher energy. High field thermodynamic measurements are used to
establish the phase diagram, revealing a substantial asymmetry of the
quintuplet condensate. This striking effect, all but absent for the triplet
condensate, is due to a fundamental asymmetry in quantum fluctuations of the
paramagnetic phases near the various critical fields.
