## Quantum Tunneling and Phase Transitions in Spin Systems with an Applied Magnetic Field

• Transitions from classical to quantum behaviour in a spin system with two degenerate ground states separated by twin energy barriers which are asymmetric due to an applied magnetic field are investigated. It is shown that these transitions can be interpreted as first- or second-order phase transitions depending on the anisotropy and magnetic parameters defining the system in an effective Lagrangian description.

Author: S.-Y. Lee, H. J. W. Müller-Kirsten, F. Zimmerschied, D.K. Park urn:nbn:de:hbz:386-kluedo-8650 Preprint English 1998 1998 Technische Universität Kaiserslautern 2000/04/03 Fachbereich Physik 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik Standard gemäß KLUEDO-Leitlinien vor dem 27.05.2011

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