Field-induced commensurate long-range order in the Haldane-gap system
Physics Department, Brookhaven National Laboratory - Upton, NY 11973, USA
2 RIKEN (The Institute of Physical and Chemical Research) Wako, Saitama 351-0198, Japan
3 Hahn-Meitner-Institut GmbH - Glienicker Str. 100, 14109 Berlin, Germany
Accepted: 29 June 2001
High-field neutron diffraction studies of the new quantum-disordered S=1 linear-chain antiferromagnet (NDMAZ) are reported. At T=70 mK, at a critical field T applied along the  direction, a phase transition to a commensurate Néel-like ordered state is observed. The results are discussed in the context of existing theories of quantum phase transitions in Haldane-gap antiferromagnets, and in comparison with previous studies of the related system (NDMAP).
PACS: 75.10.Jm – Quantized spin models / 75.30.Kz – Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.) / 75.40.-s – Critical-point effects, specific heats, short-range order
© EDP Sciences, 2001