Yang-Lee edge singularities determined from experimental high-field magnetization data

Authors

Christian Binek, University of Nebraska-LincolnFollow
Wolfgang Kleemann, Laboratorium für Angewandte Physik, Gerhard-Mercator-Universität Duisburg, D-47048 Duisburg, GermanyFollow
H. Aruga Katori, RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama 351-0198, Japan

Date of this Version

8-1-2001

Comments

Published in Journal of Physics: Condensed Matter 13 (2001), pp. L811–L817. Copyright © 2001 Institute of Physics Publishing Ltd. Used by permission. Online at stacks.iop.org/JPhysCM/13/L811

Abstract

The isothermal magnetization m (H) of the metamagnet FeCl₂ is measured in axial magnetic fields 0 ≤ μ₀H_a ≤ 12 T at temperatures 34 ≤ T ≤ 53 K above the Néel temperature, where the system is essentially a two-dimensional Ising ferromagnet. The analysis of the data indicates experimental accessibility of the critical exponent μ of the Yang-Lee edge singularities. They manifest themselves in divergences of the density functions g(θ), which quantify the distribution of the zeros of the partition function on the Lee-Yang unit circle in the complex plane. In accordance with the hypothesis of universality, a critical exponent close to the theoretical prediction for the two-dimensional Ising ferromagnet, μ = –1/6, is found.