Spectral evolution of the SU(4) Kondo effect from the single impurity to the two-dimensional lattice
Abstract
We describe the evolution of the SU(4) Kondo effect as the number of magnetic centers increases from one impurity to the two-dimensional (2D) lattice. We derive a Hubbard-Anderson model which describes a 2D array of atoms or molecules with two-fold orbital degeneracy, acting as magnetic impurities and interacting with a metallic host. We calculate the differential conductance, observed typically in experiments of scanning tunneling spectroscopy, for different arrangements of impurities on a metallic surface: a single impurity, a periodic square lattice, and several sites of a rectangular cluster. Our results point towards the crucial importance of the orbital degeneracy and agree well with recent experiments in different systems of iron(II) phtalocyanine molecules deposited on top of Au(111) [N. Tsukahara et al., Phys. Rev. Lett. 106, 187201 (2011)], indicating that this would be the first experimental realization of an artificial 2D SU(4) Kondo-lattice system.
Keywords
Cite
@article{arxiv.1305.4169,
title = {Spectral evolution of the SU(4) Kondo effect from the single impurity to the two-dimensional lattice},
author = {Alejandro M. Lobos and Marcelo Romero and Armando A. Aligia},
journal= {arXiv preprint arXiv:1305.4169},
year = {2014}
}
Comments
17 pages, 4 figures. New version contains an Appendix with details of the derivation of the Hamiltonian Eq.(2), derivation of the slave-boson mean-field equations, and an estimation of the upper bounds of the RKKY interaction