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Related papers: Charge Transfer and $dd$ excitations in AgF$_{2}$

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We investigate the electronic structure of AgF2, AgFBF4, AgF and Ag2O using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the Ag L3 edge. XAS results were compared with density functional theory…

AgF2 has been proposed as a cuprate analogue which requires strong correlation and marked covalence. On the other hand, fluorides are usually quite ionic and 4d transition metals tend to be less correlated than their 3d counterparts, which…

A semi-quantitative cluster approach is developed to describe the charge transfer (CT) electron-hole excitations in insulating cuprates in a rather wide energy range up to 10- 15 eV. It generalizes the Zhang-Ng (ZN) model of CT excitons by…

Strongly Correlated Electrons · Physics 2016-08-16 A. S. Moskvin , S. -L. Drechsler , R. Hayn , J. Málek

Using Density Functional Theory, competition between Mott-Hubbard and intervalence charge transfer mechanism of electron localization is revealed in AgF$_2$, an important silver analogue of oxocuprates. We show that at reduced temperature…

Strongly Correlated Electrons · Physics 2022-02-28 Mariana Derzsi , Kamil Tokár , Przemysław Piekarz , Wojciech Grochala

AgF2 is a layered material and a correlated charge transfer insulator with an electronic structure very similar to the parent compounds of cuprate high-Tc superconductors. It is also interesting for being a powerful oxidizer. Here we…

Materials Science · Physics 2020-10-28 Wojciech Wegner , Kamil Tokár , Jose Lorenzana , Mariana Derzsi , Wojciech Grochala

AgF$_2$ is a correlated charge-transfer insulator with properties remarkably similar to insulating cuprates which have raised hope that it may lead to a new family of unconventional superconductors upon doping. We use ab initio computations…

Strongly Correlated Electrons · Physics 2021-06-16 Subrahmanyam Bandaru , Mariana Derzsi , Adam Grzelak , Jose Lorenzana , Wojciech Grochala

The highly unusual divalent silver in silver difluoride (AgF$_2$) features a nearly square lattice of Ag$^{+2}$ bridged by fluorides. As a structural and electronic analogue of cuprates, its superconducting properties are yet to be…

Superconductivity · Physics 2022-05-04 Xiaoqiang Liu , Shishir K. Pandey , Ji Feng

We employ time-resolved optical reflectivity to investigate the ultrafast dynamics of the charge-transfer gap (CTG) in a parent cuprate compound Ca$_2$CuO$_2$Cl$_2$ (CCOC). We observe a persistent photoinduced red shift of the CTG that…

Strongly Correlated Electrons · Physics 2025-05-23 Haiyun Huang , Xiu Zhang , Junzhi Zhu , Jianfa Zhao , Lin Zhao , Yu-Xia Duan , Jian-Qiao Meng , X. J. Zhou , Changqing Jin , Haiyun Liu

The parent compound of high-Tc superconducting cuprates is a unique Mott state consisting of layers of spin-1/2 ions arranged on a square lattice and with a record high antiferromagnetic coupling within the layers. Compounds with similar…

As-grown AgF2 has a remarkably similar electronic structure as insulating cuprates, but it is extremely electronegative, which makes it hard to handle and dope. Furthermore, buckling of layers reduces magnetic interactions and enhances…

Strongly Correlated Electrons · Physics 2020-08-19 Adam Grzelak , Haibin Su , Xiaoping Yang , Dominik Kurzydłowski , Jose Lorenzana , Wojciech Grochala

The two-dimensional organic conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ undergoes a metal-insulator transition at $T_{\rm CO}=135$ K due to electronic charge ordering. We have conducted time-resolved investigations of its electronic properties…

Strongly Correlated Electrons · Physics 2016-06-15 Tobias Peterseim , Tomislav Ivek , Dieter Schweitzer , Martin Dressel

We study the electronic excitations near the charge-transfer gap in insulating CuO$_2$ planes, starting from a six-band model which includes $% p_\pi $ and $d_{xy}$ orbitals and Cu-O nearest-neighbor repulsion $U_{pd}$. While the low lying…

Condensed Matter · Physics 2016-08-15 M. E. Simón , A. A. Aligia , C. D. Batista , E. R. Gagliano , F. Lema

The parent compounds of the high-temperature cuprate superconductors are Mott insulators. It has been generally agreed that understanding the physics of the doped Mott insulators is essential to understanding the mechanism of high…

We show from a bond valence sum correlation that very high superconducting $ T_{c} $ values should be found in optimally hole-doped infinite-layer ACuO$ _{2} $ cuprates - up to 160~K for A = Ba. The projected increase in $ T_{c} $ across…

Superconductivity · Physics 2016-12-07 B. P. P. Mallett , N. Gaston , J. G. Storey , G. V. M. Williams , A. B. Kaiser , J. L. Tallon

Based on the Density Functional Theory calculations, we propose a new pathway toward compounds featuring flat [AgF2] layers which mimic [CuO2] layers in high-temperature oxocuprate superconductor precursors. Calculations predict the dynamic…

Materials Science · Physics 2024-12-17 Daniel Jezierski , Jose Lorenzana , Wojciech Grochala

A large body of experimental data point towards a charge transfer instability of parent insulating cuprates to be their unique property. We argue that the true charge transfer gap in these compounds is as small as 0.4-0.5\,eV rather than…

Strongly Correlated Electrons · Physics 2015-05-28 A. S. Moskvin

To elucidate the pressure evolution of the electronic structure in an antiferromagnetic dimer-Mott (DM) insulator ${\beta}^{\prime}$-(BEDT-TTF)$_2$ICl$_2$, which exhibits superconductivity at 14.2 K under 8 GPa, we measured the polarized…

Strongly Correlated Electrons · Physics 2015-09-01 K. Hashimoto , R. Kobayashi , H. Okamura , H. Taniguchi , Y. Ikemoto , T. Moriwaki , S. Iguchi , M. Naka , S. Ishihara , T. Sasaki

The recent observations of superconductivity at temperatures up to 55K in compounds containing layers of iron arsenide have revealed a new class of high temperature superconductors that show striking similarities to the more familiar…

There exists increasing evidence that the phase diagram of the high-transition temperature (Tc) cuprate superconductors is controlled by a quantum critical point. One distinct theoretical proposal is that, with decreasing hole-carrier…

Superconductivity · Physics 2012-10-25 Yuan Li , G. Yu , M. K. Chan , V. Baledent , Yangmu Li , N. Barisic , X. Zhao , K. Hradil , R. A. Mole , Y. Sidis , P. Steffens , P. Bourges , M. Greven

Infrared reflection measurements of the half-filled two-dimensional organic conductors $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_{2}$]Br$_{x}$Cl$_{1-x}$ were performed as a function of temperature ($5 {\rm K}<T<300$ K) and Br-substitution ($x=0%$,…

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