Related papers: Inhomogeneously doped two-leg ladder systems
We have investigated quantum critical behavior in the doped two-leg extended Hubbard ladder, by using a weak-coupling bosonization method. In the ground state, the dominant fluctuation changes from the conventional d-wave-like…
We perform variational Monte Carlo simulations of the single-band Hubbard model on the square lattice with both nearest ($t$) and next-nearest ($t'$) neighbor hoppings. Our work investigates the consequences of increasing hole doping on the…
Pairing of mobile charge carriers in doped antiferromagnets plays a key role in the emergence of unconventional superconductivity. In these strongly correlated materials, the pairing mechanism is often assumed to be mediated by magnetic…
We investigate a possibility of holon pairing for bose condensation based on the Bethe-Salpeter equation obtained from the use of the t-J Hamiltonians of both t he U(1) and SU(2) slave-boson symmetries. It is shown that the vertex function…
The Hubbard and closely related $t\text-J$ models are exciting platforms for unconventional superconductivity (SC). Through state-of-the-art density matrix renormalization group calculations using the grand canonical ensemble, we address…
The co-existence of band Jahn-Teller (BJT) effect with superconductivity (SC) is studied for correlated systems, with orbitally degenerate bands using a simple model. The Hubbard model for a doubly degenerate orbital with the on-site…
A key step in unraveling the mysteries of materials exhibiting unconventional superconductivity is to understand the underlying pairing mechanism. While it is widely agreed upon that the pairing glue in many of these systems originates from…
A two-band Hubbard model is used to describe the band structure and phase separation (PS) in multiband superconductors, especially in cuprates. We predict a large peak in the density of states at the Fermi level in the case of optimum…
We study the dynamics of the Cooper pairing across the T=0 phase diagram of the two-dimensional Hubbard Model, relevant for high-temperature superconductors, using a cluster extension of dynamical mean field theory. We find that the…
We propose that when the Fermi level lies within a wide band and also lies close to but not within a coexisting narrow band, high $T_c$ superconductivity may take place due to the large number of interband pair scattering channels and the…
An effective Hamiltonian for the Kohn-Luttinger superconductor is constructed and solved in the BCS approximation. The method is applied to the t-t' Hubbard model in two dimensions with the following results: (i) The superconducting phase…
The square-lattice Hubbard and closely related $t$-$J$ models are considered as basic paradigms for understanding strong correlation effects and unconventional superconductivity (SC). Recent large-scale density matrix renormalization group…
The Hubbard and related models serve as a fundamental starting point in understanding the novel experimental phenomena in correlated electron materials, such as superconductivity, Mott insulator, magnetism and stripe phases. Recent…
We have used exact diagonalization and quantum Monte Carlo methods to study the one-dimensional {t-J} model including the three-site hopping term derived from the strong coupling limit of the Hubbard model. The three-site term may be…
The interlayer pair-tunneling (ILT) mechanism for high-$T_c$ superconductivity is able to predict the dependence of the (optimal) critical temperature Tc on the number of layers n within an homologous series of layered cuprate oxides. We…
Traditionally one and two-point correlation functions are used to characterize many-body systems. In strongly correlated quantum materials, such as the doped 2D Fermi-Hubbard system, these may no longer be sufficient because higher-order…
We use the two dimensional extended Hubbard Hamiltonian with the position of the attractive potential as a variable parameter with a BCS type approach to study the interplay between the superconductor transition temperature $T_c$ and hole…
We study the Kane-Mele-Hubbard model both at half-filling and away from half-filling using a slave-boson mean-field approach at zero temperature. We obtain a phase diagram at half-filling and discuss its connection to recent results from…
Random bond disorder in antiferromagnetic spin-1/2 Heisenberg ladders is investigated using the Stochastic Series Expansion Quantum Monte Carlo method. We find that the effects of individual bond impurities vary strongly, depending on their…
We present an exact diagonalization study of the doping dependence of the single particle Green's function in 16, 18 and 20 site clusters of t-J model. We find evidence for rigid-band behaviour starting from the half-filled case: upon…