Role of layer packing for the electronic properties of the organic superconductor<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>BEDT</mml:mi><mml:mo>−</mml:mo><mml:mi>TTF</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mi>Ag</mml:mi><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:msub><mml:mi>CF</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mo>)</mml:mo></mml:mrow><mml:mn>4</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi

Altmeyer, Michaela; Valentí, Roser; Jeschke, Harald O.

doi:10.1103/physrevb.91.245137

Cited by 10 publications

(10 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The calculated parameters are listed in Table I. In the case of (ET) 2 Ag(CF 3 ) 4 (TCE) polymorphs (TCE abbreviates 1,1,2-trichloroethane) we rely on a previous ab initio calculation with identical setup 59 . The small asymmetry of hoppings due to the lowered symmetry in these materials is averaged out to obtain a four-parameter model.…”

Section: A Ab-initio Calculationsmentioning

confidence: 99%

Near-degeneracy of extendeds+dx2−y2anddxy

et al. 2016

Self Cite

View full text Add to dashboard Cite

The symmetry of the superconducting order parameter in quasi-two-dimensional BEDT-TTF organic superconductors is a subject of ongoing debate. We report ab initio density functional theory calculations for a number of organic superconductors containing κ-type layers. Using projective Wannier functions we derive parameters of a common low-energy Hamiltonian based on individual BEDT-TTF molecular orbitals. In a random phase approximation spin-fluctuation approach we investigate the evolution of the superconducting pairing symmetry within this model and point out a phase-transition between extended s + d x 2 −y 2 and dxy symmetry. We discuss the origin of the mixed order parameter and the relation between the realistic molecule description and the widely used dimer approximation. Based on our ab initio calculations we position the investigated materials in the obtained molecule model phase diagram and simulate scanning tunneling spectroscopy experiments for selected cases. Our calculations show that many κ-type materials lie close to the phase transition line between the two pairing symmetry types found in our calculation, possibly explaining the multitude of contradictory experiments in this field.

show abstract

Section: A Ab-initio Calculationsmentioning

confidence: 99%

Near-degeneracy of extendeds+dx2−y2anddxy

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…In previous works, a fourfold rotational symmetry constraint was introduced based on single-band Hubbard-type models proposed for these systems with a dimer of molecules per site on an anisotropic triangular lattice [23,25,[41][42][43]. Inspired by recent ab initio studies [44,45] we however went back to the original κ-type lattice structure and treated all molecules as entities. As a consequence, we find evidence for a mixed-symmetry extended s + d x 2 −y 2 state, which has been suggested to exist in some parameter regions of various models for κ-type charge-transfer salts [26,46,47], but has so far not been shown to exist in a material-specific Hamiltonian.…”

mentioning

confidence: 99%

Evidence for Eight-Node Mixed-Symmetry Superconductivity in a Correlated Organic Metal

et al. 2016

Self Cite

View full text Add to dashboard Cite

We report on a combined theoretical and experimental investigation of the superconducting state in the quasi-two-dimensional organic superconductor κ-(ET)_{2}Cu[N(CN)_{2}]Br. Applying spin-fluctuation theory to a low-energy, material-specific Hamiltonian derived from ab initio density functional theory we calculate the quasiparticle density of states in the superconducting state. We find a distinct three-peak structure that results from a strongly anisotropic mixed-symmetry superconducting gap with eight nodes and twofold rotational symmetry. This theoretical prediction is supported by low-temperature scanning tunneling spectroscopy on in situ cleaved single crystals of κ-(ET)_{2}Cu[N(CN)_{2}]Br with the tunneling direction parallel to the layered structure.

show abstract

“…Single‐band Hubbard‐type models with a dimer of molecules per site on an anisotropic triangular lattice represent minimal models that were initially proposed for organic superconductors in the κ ‐phase . Recent ab initio studies consider multiband models on a frustrated lattice resulting from the highest occupied molecular orbitals of the individual BEDT‐TTF molecules …”

Section: Low Temperature Density Of States and Superconductivity In Omentioning

confidence: 99%

Investigation of Many‐Body Effects in the Quasi‐Two‐Dimensional Electronic System of Organic Charge‐Transfer Salts

Mashoff

Regel

Medjanik

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

This article reviews recent progress in the understanding of many‐body effects in the quasi‐two‐dimensional electronic system of organic charge‐transfer salts using element‐selective X‐ray absorption and scanning tunneling spectroscopy techniques. A few previously unpublished topographical scanning tunneling microscopy images illustrate structural consequences of the charge transfer mechanism. The first part of the review focuses on the understanding of the charge transfer between acceptor and donor molecules in general. Results for dithiophene‐based organic semiconductors as a representative model system is reviewed that is relevant for electronic applications, too. Experimental results are used to develop appropriate calculation schemes with large predictive power. The combination of experiment and theory reveals a charge transfer mechanism that is more complex than just the interaction of single HOMO and LUMO states in donor and acceptor molecules. The second part of the review highlights the emergence of superconductivity as a result of the charge transfer leaving strongly correlated and partly occupied electronic states at the Fermi level. The authors review recent experimental results for the κ‐phase organic superconductors obtained with scanning tunneling spectroscopy and compare the temperature‐dependent local density of states function with theoretical approaches. The superconducting order parameter for κ‐(ET)2Cu[N(CN)2]Br reveals an eight‐node gap structure resulting from a strongly anisotropic mixed‐symmetry superconducting gap.

show abstract

Role of layer packing for the electronic properties of the organic superconductor(BEDT−TTF)2Ag(CF3)4(

Cited by 10 publications

References 30 publications

Near-degeneracy of extendeds+dx2−y2anddxy

Near-degeneracy of extendeds+dx2−y2anddxy

Evidence for Eight-Node Mixed-Symmetry Superconductivity in a Correlated Organic Metal

Investigation of Many‐Body Effects in the Quasi‐Two‐Dimensional Electronic System of Organic Charge‐Transfer Salts

Contact Info

Product

Resources

About