J Phys Condens Matter. 2013 Sep 25;25(38):385603. doi: 10.1088/0953-8984/25/38/385603. Epub 2013 Aug 30.

Absence of superconductivity and valence bond order in the Hubbard-Heisenberg model for organic charge-transfer solids.

Journal of physics. Condensed matter : an Institute of Physics journal

N Gomes, R T Clay, S Mazumdar

PMID: 23995074 DOI: 10.1088/0953-8984/25/38/385603

Abstract

A frustrated, effective ½-filled band Hubbard-Heisenberg model has been proposed for describing the strongly dimerized charge-transfer solid families κ-(ET)2X and Z[Pd(dmit)2]2. In addition to showing unconventional superconductivity, these materials also exhibit antiferromagnetism, candidate spin-liquid phases, and, in the case of Z=EtMe3P, a spin-gapped phase that has sometimes been referred to as a valence bond solid. We show that neither superconductivity nor the valence bond order phase occurs within the Hubbard-Heisenberg model. We suggest that a description based on ¼-filling, that is reached when the carrier concentration per molecule instead of per dimer is considered, thus may be appropriate.

Publication Types

• Journal Article
• Research Support, U.S. Gov't, Non-P.H.S.