Abstract
The recent discovery of superconductivity under high pressure in the ladder compound BaFe2S3 has opened a new field of research in iron-based superconductors with focus on quasi-one-dimensional geometries. In this publication, using the density matrix renormalization group technique, we study a two-orbital Hubbard model defined in one-dimensional chains. Our main result is the presence of hole binding tendencies at intermediate Hubbard U repulsion and robust Hund coupling JH/U=0.25. Binding does not occur either in weak coupling or at very strong coupling. The pair-pair correlations that are dominant near half-filling, or of similar strength as the charge and spin correlation channels, involve hole-pair operators that are spin singlets, use nearest-neighbor sites, and employ different orbitals for each hole. The Hund coupling strength, presence of robust magnetic moments, and antiferromagnetic correlations among them are important for the binding tendencies found here.
| Original language | English |
|---|---|
| Article number | 024520 |
| Journal | Physical Review B |
| Volume | 96 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jul 31 2017 |
Funding
N.D.P., A.M., and E.D. were supported by the National Science Foundation Grant No. DMR-1404375. A.N. was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Science (BES), Materials Science and Engineering Division. Part of this work was conducted at the Center for Nanophase Materials Sciences, sponsored by the Scientific User Facilities Division (SUFD), BES, DOE, under contract with UT-Battelle. G.A. acknowledges support by the Early Career Research program, SUFD, BES, DOE. Computer time was provided in part by resources supported by the University of Tennessee and Oak Ridge National Laboratory Joint Institute for Computational Sciences.