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

doi:10.1103/physrevb.94.024515

Cited by 42 publications

(87 citation statements)

References 83 publications

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“…As discussed in [35], this two-orbital model reduces to the single-band Hubbard model (at half filling), when the intradimer hopping is very large…”

Section: Model and Methodsmentioning

confidence: 99%

“…In addition, the existence of a dipolar spin-liquid phase has been suggested [29,30] (possibly also explaining the dielectric anomaly in κ-(ET) 2 Cu 2 (CN) 3 [31]). Furthermore, the two-orbital Hubbard model has been claimed to be relevant for the description of superconductivity in charge-transfer salts [32][33][34][35], including its proximity to charge-ordered phases [36,37]. In addition, spin and charge fluctuations near the metal-insulator transition in multiorbital models have been analyzed [38].…”

Section: Introductionmentioning

confidence: 99%

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Charge orders in organic charge-transfer salts

et al. 2017

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Motivated by recent experimental suggestions of charge-order-driven ferroelectricity in organic charge-transfer salts, such as κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Cl, we investigate magnetic and charge-ordered phases that emerge in an extended twoorbital Hubbard model on the anisotropic triangular lattice at 3/4 filling. This model takes into account the presence of two organic BEDT-TTF molecules, which form a dimer on each site of the lattice, and includes short-range intramolecular and intermolecular interactions and hoppings. By using variational wave functions and quantum Monte Carlo techniques, we find two polar states with charge disproportionation inside the dimer, hinting to ferroelectricity. These charge-ordered insulating phases are stabilized in the strongly correlated limit and their actual charge pattern is determined by the relative strength of intradimer to interdimer couplings. Our results suggest that ferroelectricity is not driven by magnetism, since these polar phases can be stabilized also without antiferromagnetic order and provide a possible microscopic explanation of the experimental observations. In addition, a conventional dimer-Mott state (with uniform density and antiferromagnetic order) and a nonpolar charge-ordered state (with charge-rich and charge-poor dimers forming a checkerboard pattern) can be stabilized in the strong-coupling regime. Finally, when electron-electron interactions are weak, metallic states appear, with either uniform charge distribution or a peculiar 12-site periodicity that generates honeycomb-like charge order.

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“…As discussed in [35], this two-orbital model reduces to the single-band Hubbard model (at half filling), when the intradimer hopping is very large…”

Section: Model and Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Charge orders in organic charge-transfer salts

et al. 2017

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“…For correlated metals, e.g., iron‐based superconductors and transition metal oxides, on the other hand, the electronic properties can be satisfactorily described by a combination of DFT and a many‐body technique like DMFT . Another case of interest are organic superconductors, such as

κ ‐ {(E T)}_{2} X

, the superconducting properties of which can be reliably captured by the RPA technique with tight‐binding parameters obtained from DFT . Here, however, we focus on the properties and phenomena that can be quantitatively described within a DFT‐based framework.…”

Section: Methodsmentioning

confidence: 99%

Microscopic Modeling of Correlated Systems Under Pressure: Representative Examples

Borisov

Biswas

et al. 2019

Physica Status Solidi (b)

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The complex interplay between different order parameters in correlated systems can be finely tuned by mechanical pressure giving access to a variety of distinct phases and thereby providing new functionalities. This review addresses the challenges in the state‐of‐the‐art theoretical simulations of pressure‐induced phenomena on a few representative examples of correlated systems that are currently in the focus of on‐going contemporary research. These include organic charge‐transfer multiferroics, unconventional iron‐based superconductors, frustrated quantum magnets, and candidate systems for Kitaev physics. All these systems show pronounced structural response to moderate pressures or even structural transitions to new phases which can be successfully addressed from first principles. The simulation techniques and general trends in pressure effects are discussed for each material class.

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“…Previous work focused mostly on the frustrated regime 0 ≤ t /t ≤ 1 (square lattice to triangular lattice) since these anisotropy values, usually obtained from ab initio calculations, [14][15][16][17][18] corresponded to all known BEDT organic compounds. Theoretical investigations that were concerned with the Mott transition in the interactionfrustration (U/t − t /t) phase diagram used methods that included path-integral renormalization group 19 …”

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confidence: 99%

Mott transition and magnetism on the anisotropic triangular lattice

et al. 2016

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Spin-liquid behavior was recently suggested experimentally in the moderately one-dimensional organic compound κ-H3(Cat-EDT-TTF)2. This compound can be modeled by the one-band Hubbard model on the anisotropic triangular lattice with t /t 1.5, where t is the minority hopping. It thus becomes important to extend previous studies, that were performed in the range 0 ≤ t /t ≤ 1.2, to find out whether there is a regime where Mott insulating behavior can be found without longrange magnetic order. To this end, we study the above model in the range 1.2 ≤ t /t ≤ 2 using cluster dynamical mean-field theory (CDMFT). We argue that it is important to choose a symmetrypreserving cluster rather than a quasi one-dimensional cluster. We find that, upon increasing t /t beyond t /t ≈ 1.3, the Mott transition at zero-temperature is replaced by a first-order transition separating a metallic state from a collinear magnetic insulating state. Nevertheless, at the physically relevant value t /t 1.5, the transitions toward the magnetic and the Mott insulating phases are very close. The phase diagram obtained in this study can provide a working basis for moderately one-dimensional compounds on the anisotropic triangular lattice.

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Near-degeneracy of extendeds+dx2−y2anddxy

Cited by 42 publications

References 83 publications

Charge orders in organic charge-transfer salts

Charge orders in organic charge-transfer salts

Microscopic Modeling of Correlated Systems Under Pressure: Representative Examples

Mott transition and magnetism on the anisotropic triangular lattice

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