Related papers: Evidence for short range orbital order in paramagn…
LDA+DMFT, the computation scheme merging the local density approximation and the dynamical mean-field theory, is employed to calculate spectra both below and above the Fermi energy and spin and orbital occupations in the correlated…
Motivated by recent theoretical and experimental controversy, we present a theoretical study to clarify the orbital symmetry of the ground state of vanadium spinel oxides AV$_2$O$_4$ (A=Zn, Mg, Cd). The study is based on an effective…
Here we report on the low-energy excitations within the paramagnetic spin-orbit insulator Sr$_3$Ir$_2$O$_7$F$_2$ studied via resonant inelastic X-ray scattering, \textit{ab initio} quantum chemical calculations, and model-Hamiltonian…
We present a detailed account of the physics of Vanadium sesquioxide (${\rm V_2O_3}$), a benchmark system for studying correlation induced metal-insulator transition(s). Based on a detailed perusal of a wide range of experimental data, we…
We performed first-principle calculations based on the supercell and cluster approaches to investigate the neutral Al impurity in smoky quartz. Electron paramagnetic resonance measurements suggest that the oxygens around the Al center…
The electronic structures of multiferroic oxides of Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) (0 < x < 0.12) have been investigated by employing photoemission spectroscopy and soft x-ray absorption spectroscopy (XAS). The measured Fe and Ti 2p XAS…
Using density functional theory calculations including an on-site Coulomb term, we explore electronic and possibly topologically nontrivial phases in $3d$ transition metal oxide honeycomb layers confined in the corundum structure…
Spin density waves, based on modulated local moments, are usually associated with metallic materials, but have recently been reported in insulators which display coupled magnetic and structural order parameters. We discuss one such example,…
Recent finding of an {\it unusual} in-plane resistivity anisotropy in the underdoped 122-family at high temperature ($T$) suggests an orbital nematic (ON) order, posing a challenge to extant theories. The {\it sign} of the anisotropy…
We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In La$_{1.67}$Sr$_{0.33}$NiO$_4$, polaron localization is found to suppress the low-energy…
We use resonant X-ray scattering at the nickel L$_{2,3}$ edges to investigate the interplay between orbital degrees of freedom and charge density waves (CDW) in the superconductor BaNi$_2$(As$_{1-x}$P$_x$)$_2$. Both the incommensurate and…
A simple effective model for a description of magnetically ordered insulators is analysed. The tight binding Hamiltonian consists of the effective on-site interaction (U) and intersite magnetic exchange interactions (Jz, Jxy) between…
The crystal structure of the MAPbI$_3$ hybrid perovskite forms an intricate electrostatic puzzle with different ordering patterns of the MA molecules at elevated temperatures. For this perovskite three published model Hamiltonians based on…
The hidden order (HO) in URu2Si2 has been determined as a high rank multipole formed by itinerant 5f-electrons with distinct orbital structure imposed by the crystalline electric field. Because this can lead to a considerable number of…
With infrared ellipsometry we studied the response of the confined electrons in a $\gamma$-Al$_2$O$_3$/SrTiO$_3$ heterostructures in which they originate predominantly from oxygen vacancies. From the analysis of a so-called Berreman mode,…
Aluminum monofluoride (AlF) is a suitable molecule for laser cooling and trapping. Such experiments require an extensive spectroscopic characterization of the electronic structure. Two of the theoretically predicted higher lying triplet…
The nature of order in low-temperature phases of some materials is not directly seen by experiment. Such "hidden orders" (HO) may inspire decades of research to identify the mechanism underlying those exotic states of matter. In insulators,…
The unique features of ultrafast spin dynamics and the absence of macroscopic magnetization in antiferromagnetic (AFM) materials provide a distinct route towards high-speed magnetic storage devices with low energy consumption and high…
The competition between long-range and short-range interactions among holes moving in an antiferromagnet (AF), is studied within a model derived from the spin density wave picture of layered transition metal oxides. A novel numerical…
In order to gain insight into suppression of the ferromagnetic ordering temperature, local studies utilizing 99,101Ru zero-field spin-echo NMR, along with complimentary magnetization, high-angle x-ray diffraction, and Ru K-edge XAFS…