Strongly correlated flat-band systems: The route from Heisenberg spins to Hubbard electrons
Abstract
In this review we recapitulate the basic features of the flat-band spin systems and briefly summarize earlier studies in the field. Main emphasis is made on recent developments which include results for both spin and electron flat-band models. In particular, for flat-band spin systems we highlight field-driven phase transitions for frustrated quantum Heisenberg antiferromagnets at low temperatures, chiral flat-band states, as well as the effect of a slight dispersion of a previously strictly flat band due to nonideal lattice geometry. For electronic systems, we discuss the universal low-temperature behavior of several flat-band Hubbard models, the emergence of ground-state ferromagnetism in the square-lattice Tasaki-Hubbard model and the related Pauli-correlated percolation problem, as well as the dispersion-driven ground-state ferromagnetism in flat-band Hubbard systems. Closely related studies and possible experimental realizations of the flat-band physics are also described briefly.
Keywords
Cite
@article{arxiv.1502.02729,
title = {Strongly correlated flat-band systems: The route from Heisenberg spins to Hubbard electrons},
author = {Oleg Derzhko and Johannes Richter and Mykola Maksymenko},
journal= {arXiv preprint arXiv:1502.02729},
year = {2015}
}
Comments
72 pages, 20 figures, 157 references; accepted for publication in International Journal of Modern Physics B