A5055334391- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Transition Metal Oxide Nanomaterials
- Electronic and Structural Properties of Oxides
- Perovskite Materials and Applications
- Advanced Chemical Physics Studies
- Inorganic Fluorides and Related Compounds
- Catalysis and Oxidation Reactions
- Multiferroics and related materials
- Quantum many-body systems
- Thermal properties of materials
- Spectroscopy and Quantum Chemical Studies
- Copper-based nanomaterials and applications
- Advanced Thermoelectric Materials and Devices
- Machine Learning in Materials Science
- Crystal Structures and Properties
- Thermal Expansion and Ionic Conductivity
- Ga2O3 and related materials
- Chemical and Physical Properties of Materials
- ZnO doping and properties
- Solid-state spectroscopy and crystallography
ETH Zurich
2021-2024
Wolfgang Pauli Institute
2024
A combined density functional theory and resonant elastic x-ray scattering technique is implemented to demonstrate the role of charge multipole correlation order in a 5$d$${}^{1}$ double perovskite compound that driven by complex coupled spin, charge, multipole, structural order.
We calculate the screened electron-electron interaction for charge-disproportionated insulator <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>CaFeO</a:mi><a:mn>3</a:mn></a:msub></a:math> using constrained random-phase approximation (cRPA). While in many correlated materials formation of a Mott-insulating state is driven by large local Coulomb repulsion, represented Hubbard <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>U</b:mi></b:math>, several cases have...
We investigate the interplay of spin-orbit coupling, electronic correlations, and lattice distortions in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>5</a:mn><a:msup><a:mi>d</a:mi><a:mn>1</a:mn></a:msup></a:mrow></a:math> double perovskite <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:msub><b:mi>Ba</b:mi><b:mn>2</b:mn></b:msub><b:msub><b:mi>MgReO</b:mi><b:mn>6</b:mn></b:msub></b:mrow></b:math>. Combining density-functional theory (DFT) dynamical...
We present a combined density-functional theory and single-site dynamical mean-field (DMFT) study of vanadium dioxide <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mo>(</a:mo><a:msub><a:mi>VO</a:mi><a:mn>2</a:mn></a:msub><a:mo>)</a:mo></a:math> using an unconventional set bond-centered orbitals as the basis correlated subspace. <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msub><b:mi>VO</b:mi><b:mn>2</b:mn></b:msub></b:math> is prototypical material undergoing...
Strongly correlated systems are a class of materials whose electronic structure is heavily influenced by the effect electron-electron interactions.In these systems, an effective singleparticle description may not capture many-body effects accurately.Although density functional theory (DFT) plus dynamical mean-field (DMFT) has proven successful in describing strongly electron for over two decades, only very recently ready-to-use software packages have begun to become available, with most...
Clarifying the underlying mechanisms that govern ordering transitions in condensed matter systems is crucial for comprehending emergent properties and phenomena. While are often classified as electronically driven or lattice-driven, we present a departure from this conventional picture case of double perovskite Ba2MgReO6. Leveraging resonant non-resonant elastic x-ray scattering techniques, unveil simultaneous structural distortions charge quadrupoles at critical temperature Tq ~ 33 K. Using...
We explore the transition to a charge-disproportionated insulating phase in five-orbital cubic tight-binding model applicable transition-metal perovskites with formal ${d}^{4}$ occupation of cation, such as ferrates or manganites. use dynamical mean-field theory obtain diagram function average local Coulomb repulsion $U$ and Hund's coupling $J$. The main structure follows from zero bandwidth (atomic) limit represents competition between high-spin low-spin homogeneous an inhomogeneous state....
We present a method to constrain local charge multipoles within density-functional theory. Such quantify the anisotropy of distribution around atomic sites and can indicate potential hidden orders. Our allows selective control specific multipoles, facilitating quantitative exploration energetic landscape outside minima. Thus, it enables clear distinction between electronically structurally driven instabilities. demonstrate effectiveness this by applying quadrupoles in prototypical orbitally...
We address the problem of analytic continuation imaginary-frequency Green's functions, which is crucial in many-body physics, using machine learning based on a multilevel residual neural network. specifically potential biases that can be introduced due to use artificially created spectral functions are employed train also implement an uncertainty estimation predicted function, Monte Carlo dropout, allows us identify frequency regions where prediction might not accurate, and we study effect...
We calculate the screened electron-electron interaction for charge-disproportionated insulator CaFeO$_3$ using constrained random-phase approximation (cRPA). While in many correlated materials, formation of a Mott-insulating state is driven by large local Coulomb repulsion, represented Hubbard $U$, several cases have been identified more recently where $U$ strongly and instead Hund's $J$ dominates physics. Our results confirm strong screening repulsion whereas much less can thus stabilize...
Clarifying the underlying mechanisms that govern ordering transitions in condensed matter systems is crucial for comprehending emergent properties and phenomena. While are often classified as electronically driven or lattice-driven, we present a departure from this conventional paradigm case of double perovskite Ba$_2$MgReO$_6$. Leveraging resonant non-resonant elastic x-ray scattering techniques, unveil simultaneous structural distortions charge quadrupoles at critical temperature...
We present a combined density-functional theory and single-site dynamical mean-field (DMFT) study of vanadium dioxide (VO$_2$) using an unconventional set bond-centered orbitals as the basis correlated subspace. VO$_2$ is prototypical material undergoing metal-insulator transition (MIT), hosting both intriguing physical phenomena potential for industrial applications. With our choice subspace basis, we investigate interplay structural dimerization electronic correlations in computationally...
We present a method to constrain local charge multipoles within density-functional theory. Such quantify the anisotropy of distribution around atomic sites and can indicate potential hidden orders. Our allows selective control specific multipoles, facilitating quantitative exploration energetic landscape outside minima. Thus, it enables clear distinction between electronically structurally driven instabilities. demonstrate effectiveness this by applying quadrupoles in prototypical orbitally...
We investigate the interplay of spin-orbit coupling, electronic correlations, and lattice distortions in $5d^1$ double perovskite Ba$_2$MgReO$_6$. Combining density-functional theory (DFT) dynamical mean-field (DMFT), we establish Mott-insulating character Ba$_2$MgReO$_6$ both its cubic tetragonal paramagnetic phases. Despite substantial impact on formation insulating state is minimal, consistent with theoretical expectations for $d^1$ systems. further characterize properties phases by...
We examine the role of charge, structural, and spin degrees freedom in previously poorly understood phase transition 5$d^1$ transition-metal double perovskite Cs$_2$TaCl$_6$, using a combination computational experimental techniques. Our heat capacity measurements single-crystalline reveal clear anomaly at temperature, $T_\mathrm{Q}$, which was not observed polycrystalline samples. Density functional calculations indicate emergence local charge quadrupoles cubic phase, mediated by...