Ingredients for generalized models of κ-phase organic charge-transfer salts: a review

  • The families of organic charge-transfer salts 𝜅-(BEDT-TTF)2𝑋 and 𝜅-(BETS)2𝑋, where BEDT-TTF and BETS stand for the organic donor molecules C10H8S8 and C10H8S4Se4, respectively, and X for an inorganic electron acceptor, have been proven to serve as a powerful playground for the investigation of the physics of frustrated Mott insulators. These materials have been ascribed a model character, since the dimerization of the organic molecules allows to map these materials onto a single band Hubbard model, in which the dimers reside on an anisotropic triangular lattice. By changing the inorganic unit X or applying physical pressure, the correlation strength and anisotropy of the triangular lattice can be varied. This has led to the discovery of a variety of exotic phenomena, including quantum-spin liquid states, a plethora of long-range magnetic orders in proximity to a Mott metal-insulator transition, and unconventional superconductivity. While many of these phenomena can be described within this effective one-band Hubbard model on a triangular lattice, it has become evident in recent years that this simplified description is insufficient to capture all observed magnetic and electronic properties. The ingredients for generalized models that are relevant include, but are not limited to, spin-orbit coupling, intra-dimer charge and spin degrees of freedom, electron-lattice coupling, as well as disorder effects. Here, we review selected theoretical and experimental discoveries that clearly demonstrate the relevance thereof. At the same time, we outline that these aspects are not only relevant to this class of organic charge-transfer salts, but are also receiving increasing attention in other classes of inorganic strongly correlated electron systems. This reinforces the model character that the 𝜅-phase organic charge-transfer salts have for understanding and discovering novel phenomena in strongly correlated electron systems from a theoretical and experimental point of view.

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Metadaten
Author:Kira Marina RiedlORCiDGND, Elena Aurelia GatiORCiDGND, Roser ValentíORCiDGND
URN:urn:nbn:de:hebis:30:3-824786
DOI:https://doi.org/10.3390/cryst12121689
ISSN:2073-4352
Parent Title (English):Crystals
Publisher:MDPI
Place of publication:Basel
Document Type:Article
Language:English
Date of Publication (online):2022/11/22
Date of first Publication:2022/11/22
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2024/02/16
Tag:disorder; electron-lattice coupling; intra-dimer charge and spin degrees of freedom; magnetic exchange beyond Heisenberg; organic charge-transfer salts
Volume:12
Issue:12, 1689
Article Number:1689
Page Number:28
HeBIS-PPN:517910071
Institutes:Physik / Physik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - CC BY - Namensnennung 4.0 International