| Molecule-based quantum magnets offer exciting new possibilities for exploring quantum many-body effects under variable and well-controlled conditions. Subjects of high current interest are the unusual magnetothermal effects close to a magnetic field-induced quantum critical point and the possibility to realize a Bose-Einstein condensation of magnetic excitations. We focus here on Cu2+-containing coordination polymers, which represent model systems with energy scales small enough for laboratory fields to tune the system close to their quantum critical points. We will discuss the magnetocaloric effect close to the saturation field of a uniform S = ½ antiferromagnetic Heisenberg chain and the field-induced transition, indicative of a Kosterlitz-Thouless transition, in a quasi-twodimensional coupled-dimer system. |
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