Antiferromagnetic order without recourse to staggered fields
Quantum Physics
2018-07-19 v3 Mesoscale and Nanoscale Physics
Abstract
In the theory of antiferromagnetism, the staggered field---an external magnetic field that alternates in sign on atomic length scales---is used to select the classical N\'eel state from a quantum magnet, but justification is missing. This work examines, within the decoherence framework, whether repeated measurement can replace a staggered field. Accordingly, the conditions under which local decoherence can be considered a continuous measurement are studied. The dynamics of a small magnetic system is analysed to illustrate that local decoherence can lead to (symmetry-broken) order similar to order resulting from a staggered field.
Cite
@article{arxiv.1711.07738,
title = {Antiferromagnetic order without recourse to staggered fields},
author = {H. C. Donker and H. De Raedt and M. I. Katsnelson},
journal= {arXiv preprint arXiv:1711.07738},
year = {2018}
}