Related papers: Conducting phase in the two-dimensional disordered…
We study the half filled extended Hubbard model on a two-dimensional square lattice using cluster dynamical mean field theory on clusters of size 8-20. We show that the model exhibits metallic, Mott insulating, and charge ordered phases,…
We investigate the phase diagram of two-dimensional (2D) Hubbard model by employing the optimization variational Monte Carlo method. The 2D Hubbard model is the most simple electronic model for cuprate high-temperature superconductors. The…
The Hubbard model and its strong-coupling version, the Heisenberg one, have been widely studied on the triangular lattice to capture the essential low-temperature properties of different materials. One example is given by transition metal…
We establish the nonequilibrium thermal phases of a voltage driven antiferromagnetic Mott insulator in three dimensions, realised at steady state under a voltage bias. Starting from the Keldysh action for the half filled Hubbard model we…
A powerful new impurity solver is shown to permit a systematic study of the doping driven Mott transition in a one-band Hubbard model within the framework of single-site dynamical mean field theory. At small dopings and large interaction…
We have studied the metallic behaviour in low density GaAs hole systems, and Si electron systems, close to the apparent two-dimensional metal-insulator transition. Two observations suggest a semi-classical origin for the metallic-like…
We propose a scaling theory of 2D metal insulator transition discovered by Kravchenko and coworkers. In this theory conductance/resistance duality is an exact relation. The exponent of the stretched exponential in $\sigma(T)$ is determined…
We investigate metal-insulator transitions on an interacting two-dimensional Dirac fermion system using the determinant quantum Monte Carlo method. The interplay between Coulomb repulsion, disorder and magnetic fields, drives the otherwise…
The Hubbard model in the strong-coupling regime is mainly studied by Kondo-lattice theory or 1/d expansion theory, with d the spatial dimensionality. In two dimensions and higher, the ground state within the Hilbert subspace with no order…
In the absence of magnetic field or spin-orbit coupling the one-parameter scaling theory predicts localization of all states in two-dimensional (2D) disordered systems, for any amount of disorder. However, a 2D metallic phase has been…
We study the low energy behavior of the one dimensional Hubbard model across the Mott metal-insulator phase transition in an external magnetic field. In particular we calculate elements of the dressed charge matrix at the critical point of…
An electric current flowing in a ferromagnetic metal carries spin angular momentum, i.e. it is spin-polarized. Here, we measure the spin-wave Doppler shift induced by the transfer of angular momentum from the diffusive spin-polarized…
The influence of long-range spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which…
We study the strong correlation effects in the vicinity of the Mott metal-insulator transition using coupled clean or disordered Hubbard chains with a infinitely large coordinate number $D_{\perp}\to\infty$ in the direction perpendicular to…
We show that in presence of a deformable lattice potential, the nature of the disorder-driven metal-insulator transition (MIT) is fundamentally changed with respect to the non-interacting (Anderson) scenario. For strong disorder, even a…
We study the insulator-to-superfluid transition in a two-dimensional disordered boson Hubbard model at zero temperature for intermediate strength of disorder at commensurate density. Via Monte Carlo calculations of the correlation functions…
The Kane-Mele model is known to show a quantized spin Hall conductivity at zero temperature. Including Hubbard interactions at each site leads to a quantum phase transition to an XY antiferromagnet at sufficiently high interaction strength.…
Employing a recently developed many-body technique that allows for the incorporation of thermal effects, the rich phase diagram of a two dimensional two orbital (degenerate $d_{xz}$ and $d_{yz}$) Hubbard model is presented varying…
We study thermal and electrical transport in metals and superconductors near a quantum phase transition where antiferromagnetic order disappears. The same theory can also be applied to quantum phase transitions involving the loss of certain…
We report on a fully self-consistent determination of a phase transition to a superconducting state in a conserving approximation. The transition temperature calculated for a two-dimensional Hubbard model with an attractive interaction in…