Theoretical study on the iron-based two-leg ladder tellurides*

The recent discovery of superconductivity in the two-leg ladder compounds BaFe₂X₃ (X=S, Se) started the novel field of quasi-one-dimensional iron-based superconductors. Here, we predict that the previously barely explored ladder compound RbFe₂Te₃ should be magnetic with a CX-type arrangement[1]. Moreover, at n = 6.0 our DFT phase diagrams (with/without lattice tetramerization) reveal that the stable magnetic states could be either a 2x2 magnetic Block-type, as for X=Se, or a previously never observed before CY-type state. In the Te-based studies, electrons are more localized than in S, implying that the degree of electronic correlation is enhanced for the Te case. This potential relevance of strong correlation in n=6 Te-123 ladders could also induce exotic phenomena [2], such as Block-type order, the orbital selective Mott physics, and superconductivity under high pressure. Our overarching conclusion is that experimental studies of iron ladder tellurides are worth pursuing.

[1] Y. Zhang, L. F. Lin, A. Moreo, S. Dong and E. Dagotto, arXiv:1908.11765.
[2] Y. Zhang, L. F. Lin, A. Moreo, S. Dong and E. Dagotto (in preparation).