Proximity of the Layered Organic Conductorsα−(BEDT−TTF)2MHg(SCN)4(M=K,NH4)to a Charge-Ordering Transition

2002/06/06 by Martin Dressel, M. Dressel, N. Drichko +5 · 4 citations
Chemistry · Materials Science · Physics and Astronomy · #Inorganic Chemistry and Materials #N-Heterocyclic Carbenes in Organic and Inorganic Chemistry #Organic and Molecular Conductors Research #Physics #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevlett.90.167002

4 pages, 3 figures

arxiv created 2002/06/06 · openalex publication_date 2003/04/24 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

While the optical properties of the superconducting salt \ensuremathα\mathrm\text\ensuremath-(BEDT\mathrm\text\ensuremath-TTF)₂\mathrm\text\ensuremath-NH₄Hg(SCN)₄ remain metallic down to 2 K, in the nonsuperconducting K analog a pseudogap develops at frequencies of about 200 cm^\ensuremath-1 for temperatures T<200 K. We show that the optical conductivity calculated with exact-diagonalization techniques on an extended Hubbard model at quarter filling is consistent with the observed low-frequency feature. We argue that the different optical responses observed are a consequence of the proximity of these compounds to a charge-ordering transition driven by the intermolecular Coulomb repulsion.

Citations

• Correlation gap in the optical spectra of the two-dimensional organic metal(BEDT−TTF)4[Ni(dto)2]

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