相关论文: The driving force for charge ordering in rare eart…
We develop in detail a model of the charge order in NbSe$_2$ deriving from a strong electron-phonon coupling dependent on the ingoing and outgoing electron momenta as well as the electronic orbitals scattered between. Including both…
This is the first study of the effect of pressure on transition metal dichalcogenides intercalated by atoms that order magnetically. Co$_{1/3}$NbS$_2$ is a layered system where the intercalated Co atoms order antiferromagnetically at T$_N$…
Clarifying the underlying mechanisms that govern ordering transitions in condensed matter systems is crucial for comprehending emergent properties and phenomena. While transitions are often classified as electronically driven or…
Motivated by recent experimental suggestions of charge-order-driven ferroelectricity in organic charge-transfer salts, such as $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl, we investigate magnetic and charge-ordered phases that emerge in an…
The apparent contradiction between the recently observed weak charge disproportion and the traditional Mn$^{3+}$/Mn$^{4+}$ picture of the charge-orbital orders in half-doped manganites is resolved by a novel Wannier states analysis of the…
Iron perovskites CaFeO_3 and La_{0.33}Sr_{0.67}FeO_3 show charge disproportionation, resulting in charge-ordered states with Fe^{3+}:Fe^{5+} =1:1 and =2:1, respectively. We have made photoemission and unrestricted Hartree-Fock…
Rare-earth nickelates exhibit a remarkable metal-insulator transition accompanied by a structural transition associated with a lattice `breathing' mode. Using model considerations and first-principles calculations, we present a theory of…
Superconductivity found in doped NdNiO$_2$ is puzzling as two local symmetries of doped NiO$_2$ layers compete, with presumably far-reaching implications for the involved mechanism: a cuprate-like regime with Zhang-Rice singlets {\cblue is…
In this paper we investigate the electronic and superconducting properties in nickelate compounds of NiO2 through Perturbative Density Functional Theory (P-DFT) and multi-band BCS theory. We consider three different cases of study (i) the…
We examine the various instabilities of quarter-filled strongly correlated electronic chains in the presence of a coupling to the underlying lattice. To mimic the physics of the (TMTTF)$_2$X Bechgaard-Fabre salts we also include…
The electronic transport properties and the magnetic susceptibility were measured in detail in $YBaCo_2O_{5.45}$. Close to the so-called metal-insulator transition, strong effects of resistance relaxation, a clear thermal hysteresis and a…
We report a comprehensive neutron diffraction study of the crystal structure and magnetic order in a series of single-crystal and powder samples of SrFeO$_{3-\delta}$ in the vacancy range $0 \leq \delta \leq 0.23$. The data provide detailed…
Superconducting nickelates appear to be difficult to synthesize. Since the chemical reduction of ABO3 (A: rare earth; B transition metal) with CaH2 may result in both, ABO2 and ABO2H, we calculate the topotactic H binding energy by density…
Developing a low-energy model is essential for understanding unconventional superconductivity in bilayer nickelate La$_3$Ni$_2$O$_7$. Here, we analyze distinct low-energy scenarios of the normal state by downfolding the ab-initio determined…
Modern energy applications, especially electric vehicles, demand high energy batteries. However, despite decades of intensive efforts, the highest energy density and commercially viable batteries are still based on LiCoO2, the very first…
A negative differential resistance (NDR) in the nanotransport is often ascribed to electron correlations. We present a simple example which demonstrates that finite electrode bandwidths and energy dependent electrode density of states are…
Double perovskite, (Sr1-xNdx)2FeMoO6, was doped with electrons through partial substitution of divalent Sr by trivalent Nd (0 < x < 0.2). The Fe valence and the degree of B-site order were probed by 57Fe Mossbauer spectroscopy. Replacing Sr…
By means of first-principles simulations, we unambiguously show that improper ferroelectricity in magnetite in the low-temperature insulating phase is driven by charge-ordering. An accurate comparison between monoclinic ferroelectric Cc and…
Low-valent nickelates R$_{n+1}$Ni$_n$O$_{2n+2}$ (R = rare earth) containing Ni$^{1+}$ (d$^{9}$) with a quasi-two-dimensional (quasi-2D) square planar coordination geometry possess structural and electronic properties that are similar to…
The functional characteristics of double perovskites with unique ferromagnetic-insulator ground state have been controversial due to the unavoidable presence of anti-site disorders (ASDs). Here, we aim to investigate the origin of magnetic…