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TT: Fachverband Tiefe Temperaturen
TT 2: Symposium: High Magnetic Field Phenomena in Low Dimensional Magnets
TT 2.7: Vortrag
Montag, 25. Februar 2008, 12:15–12:45, H 0104
Exploring field-induced quantum phase transitions in molecule-based magnets — •Michael Lang1, Katarina Removic-Langer1, Yeekin Tsui1, Ulrich Tutsch1, Bernd Wolf1, Andrei Prokofiev1, Wolf Assmus1, Roser Valenti2, Andreas Honecker3, Matthias Wagner4, and Stefan Wessel5 — 1Phys. Inst. Univ. Frankfurt, SFB/TR 49 — 2Inst. f. Theor. Physik, Univ. Frankfurt, SFB/TR 49 — 3Inst. f. Theor. Physik, Univ. Göttingen — 4Inst. f. Anorg. u. Analyt. Chemie, Univ. Frankfurt, SFB/TR 49 — 5Inst. f. Theor. Physik III, Univ. Stuttgart
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 (BEC) of magnetic excitations. We focus here on Cu(II)-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 = 1/2 antiferromagnetic Heisenberg chain and the field-induced BEC of magnetic excitations in a quasi-twodimensional coupled-dimer system.