Theory of Antiferromagnetic Order in High-T sub( c) Oxides: An Approach Based on Ginzburg-Landau Expansion

The mean-field phase diagram of antiferromagnetic order in t-J model has been examined, using the free energy obtained by Ginzburg-Landau (GL) expansion. We extended the usual GL theory in two ways: First, we have included higher order terms with respect to the spatial derivative (or wave number) to...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the Physical Society of Japan 2013-12, Vol.82 (12), p.1-1
Main Authors: Hayashi, Masahiko, Tanuma, Yasunari, Kuboki, Kazuhiro
Format: Article
Language:English
Subjects:
Antiferromagnetism
Derivatives
Free energy
Oxides
Phase diagrams
Phase transformations
Spin glass
Wavelengths
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The mean-field phase diagram of antiferromagnetic order in t-J model has been examined, using the free energy obtained by Ginzburg-Landau (GL) expansion. We extended the usual GL theory in two ways: First, we have included higher order terms with respect to the spatial derivative (or wave number) to incorporate the incommensurate antiferromagnetic order. Second, we have also included higher order terms with respect to the order parameter amplitude, in order to treat the first order phase transition between paramagnetic and antiferromagnetic phase, which appears at some doping rates. We found the possibility of tricritical point and critical endpoint in the magnetic phase diagram of the high-Tc oxides associated with the commensurate and incommensurate antiferromagnetic order. The possible effects of thermal fluctuations and randomness (spin glass) are also discussed qualitatively based on the GL free energy.
ISSN:0031-9015
1347-4073