Related papers: Magnetic Instability in Strongly Correlated Superc…
We report on a new electromagnetic phenomenon that emerges in Mott insulators, i.e., materials that do not conduct electricity because of strong electronic Coulomb repulsion. The phenomenon manifests as antiferromagnetic ordering due to…
Using path-integral Quantum Monte Carlo we study the low-temperature phase diagram of a two-dimensional superconductor within a phenomenological model, where vortices have a finite mass and move in a dissipative environment modeled by a…
We study, using quantum Monte-Carlo simulations, the bosonic Kondo-Hubbard model in a two dimensional square lattice. We explore the phase diagram and analyse the mobility of particles and magnetic properties. At unit filling, the…
Quantum oscillations in magnetization or resistivity are a defining feature of metals subject to an external magnetic field. The phenomenon is generally not expected in insulators without a Fermi surface. The observations of quantum…
We discuss the mechanisms of unconventional superconductivity and superfluidity in 3D and 2D fermionic systems with purely repulsive interaction at low densities. We construct phase diagrams of these systems and find the areas of the…
For the Mott insulator state of the Fermi-Hubbard model in the strong-coupling limit, we study the interaction between quasi-particles in the form of doublons and holons. Comparing different methods -- the hierarchy of correlations,…
A simple effective model of charge ordered and (or) magnetically ordered insulators is studied. The tight binding Hamiltonian analyzed consists of (i) the effective on-site interaction U, (ii) the intersite density-density interaction W and…
We theoretically study the competition among different electronic phases in molecular conductors $\kappa$-(BEDT-TTF)$_2$X. The ground-state properties of a 3/4-filled extended Hubbard model with the $\kappa$-type geometry are investigated…
We analyze superconducting instabilities in 3D and 2D extended Hubbard model with Coulomb repulsion between electrons on neighboring sites in the limit of low electron density ($n_{el} \rightarrow 0$) on simple cubic (square) lattice. We…
We present a novel geometric approach for determining the unique structure of a Hamiltonian and establishing an instability criterion for quantum quadratic systems. Our geometric criterion provides insights into the underlying geometric…
A unitary transformation is applied to the Hubbard model, which maps the Hubbard interaction to a single particle term. The resulting Hamiltonian consists of unconstrained fermions, which is then mapped to a Hamiltonian of spinless fermions…
The ground state phase diagram of the half-filled repulsive Hubbard model in a bilayer is investigated using cluster dynamical mean field theory. For weak to intermediate values of Coulomb repulsion $U$, the system undergoes a transition…
The apparently inimical relationship between magnetism and superconductivity has come under increasing scrutiny in a wide range of material classes, where the free energy landscape conspires to bring them in close proximity to each other.…
A model is introduced describing the interplay between superconductivity and spin-ordering. It is characterized by on-site repulsive electron-electron interactions, causing antiferromagnetism, and nearest-neighbor attractive interactions,…
The low-energy electronic Hamiltonian for the thinest zigzag carbon nanotube, embedded into a dielectric host, is derived and its phase diagram is discussed. The specific multi-band structure and the microscopic form of the…
It has only recently been possible to study the superconducting state in the attractive Hubbard Hamiltonian via a direct observation of the formation of a gap in the density of states N(w). Here we determine the effect of random chemical…
Cooperation and competition between the antiferromagnetic, d-wave superconducting and Mott-insulating states are explored for the two-dimensional Hubbard model including nearest and next-nearest-neighbor hoppings at zero temperature. Using…
This article surveys the physics of systems proximate to Mott insulators, and presents a classification using conventional and topological order parameters. This classification offers a valuable perspective on a variety of conducting…
We shall review our recent works on d-wave density wave (dDW) and gossamer superconductivity (i.e. d-wave superconductivity in the presence of dDW) in high-T$_{c}$ cuprates and CeCoIn$_{5}$. a) We show that both the giant Nernst effect and…
Tight-binding Hamiltonians with single and multiple orbitals exhibit an intriguing array of magnetic phase transitions. In most cases the spin ordered phases are insulating, while the disordered phases may be either metallic or insulating.…