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arXiv · 1503.07805

Role of layer packing for the electronic properties of the organic superconductor (BEDT-TTF)$_2$Ag(CF$_3$)$_4$(TCE)

Michaela Altmeyer·Roser Valenti·Harald O. Jeschke
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Abstract

The charge transfer compound (BEDT-TTF)$_2$Ag(CF$_3$)$_4$(TCE) crystallizes in three polymorphs with different alternating layers: While a phase with a $\kappa$ packing motif has a low superconducting transition temperature of $T_c=2.6$ K, two phases with higher $T_c$ of $9.5$ and $11$ K are multi-layered structures consisting of $\alpha'$ and $\kappa$ layers. We investigate these three systems within density functional theory and find that the $\alpha'$ layer shows different degrees of charge order for the two $\kappa$-$\alpha'$ systems and directly influences the electronic behavior of the conducting $\kappa$ layer. We discuss the origin of the distinct behavior of the three polymorphs and propose a minimal tight-binding Hamiltonian for the description of these systems based on projective molecular Wannier functions.

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Michaela Altmeyer, Roser Valenti, Harald O. Jeschke. 2015-03-26. Role of layer packing for the electronic properties of the organic superconductor (BEDT-TTF)$_2$Ag(CF$_3$)$_4$(TCE). https://doi.org/10.1103/physrevb.91.245137

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