Mutually attracting spin waves in the square-lattice quantum antiferromagnet
Abstract
The Heisenberg model for S=1/2 describes the interacting spins of electrons localized on lattice sites due to strong repulsion. It is the simplest strong-coupling model in condensed matter physics with wide-spread applications. Its relevance has been boosted further by the discovery of curate high-temperature superconductors. In leading order, their undoped parent compounds realize the Heisenberg model on square-lattices. Much is known about the model, but mostly at small wave vectors, i.e., for long-range processes, where the physics is governed by spin waves (magnons), the Goldstone bosons of the long-range ordered antiferromagnetic phase. Much less, however, is known for short-range processes, i.e., at large wave vectors. Yet these processes are decisive for understanding high-temperature superconductivity. Recent reports suggest that one has to resort to qualitatively different fractional excitations, spinons. By contrast, we present a comprehensive picture in terms of dressed magnons with strong mutual attraction on short length scales. The resulting spectral signatures agree strikingly with experimental data
Cite
@article{arxiv.1701.04730,
title = {Mutually attracting spin waves in the square-lattice quantum antiferromagnet},
author = {M. Powalski and K. P. Schmidt and G. S. Uhrig},
journal= {arXiv preprint arXiv:1701.04730},
year = {2018}
}
Comments
substantially extended version, 41 pages, 9 figures submitted to SciPost