Related papers: `Interaction annealing' to determine effective qua…
Moir\'e materials with flat electronic bands provide a highly controllable quantum system for studies of strong-correlation physics and topology. In particular, angle-aligned heterobilayers of semiconducting transition metal dichalcogenides…
The Hubbard model is investigated in the framework of lattice density functional theory (LDFT). The single-particle density matrix $\gamma_{ij}$ with respect the lattice sites is considered as the basic variable of the many-body problem. A…
We review theoretical concepts and models for materials with strongly correlated d- or f electrons. We discuss low-energy effective models and the renormalized band method for Ce-based Kondo lattice systems. They are applied to the analysis…
We present a comprehensive study of the spin excitations - as measured by the dynamical spin structure factor $S(q,\omega)$ - of the so-called block-magnetic state of low-dimensional orbital-selective Mott insulators. We realize this state…
We calculate the screened electron-electron interaction for the charge-disproportionated insulator CaFeO$_3$ using the constrained random-phase approximation (cRPA). While in many correlated materials, the formation of a Mott-insulating…
A new supersymmetric model for electrons with generalized hopping terms and Hubbard interaction on a one-dimensional lattice is solved by means of the Bethe Ansatz. We investigate the phase diagram of this model by studying the ground state…
One of the early triumphs of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states correctly predicts the character of most materials this…
Using $t_{2g}$ Wannier-functions, a low-energy Hamiltonian is derived for orthorhombic $3d^{1}$ transition-metal oxides. Electronic correlations are treated with a new implementation of dynamical mean-field theory for non-cubic systems.…
The nature of the effective interaction responsible for pairing in the high-temperature superconducting cuprates remains unsettled. This question has been studied extensively using the simplified single-band Hubbard model, which does not…
We used quantum chemical ab initio methods to determine the effective parameters of Hubbard and $t-J$ models for the $\rm Na_{x}CoO_2$ compounds (x=0 and 0.5). As for the superconducting compound we found the $a_{1g}$ cobalt orbitals above…
The possibility of the strong electron-electron interaction driven insulating phase from the metallic phase in two-dimensions has been suggested for clean systems without intentional disorder, but its rigorous demonstration is still…
We propose a scheme for the construction of charge and spin linear-response functions of an interacting electronic system via quantum phase estimation and statistical sampling on a quantum computer. By using the unitary decomposition of…
The interaction between localized f and itinerant conduction electrons is crucial in the electronic properties of heavy fermion and valence fluctuating compounds. Using high-resolution angle-resolved photoemission spectroscopy, we…
We describe two experiments to study the influence of fluctuations in the electron charge on the transport properties of a quantum dot. First, we scan a device from single- to double quantum-dot behavior by varying the conductance of a…
Mixed valence spinels provide a fertile playground for the interplay between charge, spin, and orbital degrees of freedom in strongly correlated electrons on a geometrically frustrated lattice. Among them, AlV$_2$O$_4$ and LiV$_2$O$_4$…
Building upon the recent progress on the intriguing underlying physics for the newly discovered infinite-layer nickelates, in this article we review an examination of valence charge and spin excitations via multi-orbital Hubbard models as…
Materials with correlated electrons often respond very strongly to external or internal influences, leading to instabilities and states of matter with broken symmetry. This behavior can be studied theoretically either by evaluating the…
Mutual Coulomb interactions between electrons lead to a plethora of interesting physical and chemical effects, especially if those interactions involve many fluctuating electrons over large spatial scales. Here, we identify and study in…
The study of entanglement in strongly correlated electron systems typically requires knowledge of the reduced density matrix. Here, we apply the parquet dynamical vertex approximation to study the two-site reduced density matrix at varying…
We analyze the role of spatial electronic correlations and, in particular, of the magnetic fluctuations in Mott insulators. A half-filled Hubbard model is solved at large strength of the repulsion U on a two-dimensional square lattice using…