Emergent Spin Excitations in a Bethe Lattice at Percolation
Strongly Correlated Electrons
2013-10-10 v2 Disordered Systems and Neural Networks
Abstract
We study the spin 1/2 quantum Heisenberg antiferromagnet on a Bethe lattice diluted to the percolation threshold. Dilution creates areas of even/odd sublattice imbalance resulting in "dangling spins" (L. Wang and A. W. Sandvik, Phys. Rev. Lett. 97, 117204 (2006); Phys. Rev. B 81, 054417 (2010)). These collectively act as "emergent" spin 1/2 degrees of freedom and are responsible for the creation of a set of low lying "quasidegenerate states". Using Density Matrix Renormalization Group (DMRG) calculations, we detect the presence and location of these emergent spins. We find an effective Hamiltonian of these emergent spins, with Heisenberg interactions that decay exponentially with the distance between them.
Keywords
Cite
@article{arxiv.1210.4621,
title = {Emergent Spin Excitations in a Bethe Lattice at Percolation},
author = {Hitesh J. Changlani and Shivam Ghosh and Sumiran Pujari and Christopher L. Henley},
journal= {arXiv preprint arXiv:1210.4621},
year = {2013}
}
Comments
4+ pages, 3 figures