Inhomogeneous $s$ -wave superconductivity is studied in the two-dimensional, square lattice attractive Hubbard Hamiltonian using the Bogoliubov-de Gennes (BdG) mean field approximation. We find that at weak coupling, and for densities mainly below half-filling, an inhomogeneous interaction in which the on-site interaction ${U}_{i}$ takes on two values, ${U}_{i}=0,\phantom{\rule{0.3em}{0ex}}2U$ results in a larger zero temperature pairing amplitude, and that the superconducting ${T}_{c}$ can also be significantly increased, relative to a uniform system with ${U}_{i}=U$ on all sites. These effects are observed for stripe, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. Monte Carlo calculations which reintroduce some of the fluctuations neglected within the BdG approach see the same effect, both for the attractive Hubbard model and a Hamiltonian with $d$ -wave pairing symmetry.Inhomogeneous $s$-wave superconductivity is studied in the two-dimensional, square lattice attractive Hubbard Hamiltonian using the Bogoliubov-de Gennes (BdG) mean field approximation. We find that at weak coupling, and for densities mainly below half-filling, an inhomogeneous interaction in which the on-site interaction ${U}_{i}$ takes on two values, ${U}_{i}=0,\phantom{\rule{0.3em}{0ex}}2U$ results in a larger zero temperature pairing amplitude, and that the superconducting ${T}_{c}$ can also be significantly increased, relative to a uniform system with ${U}_{i}=U$ on all sites. These effects are observed for stripe, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. Monte Carlo calculations which reintroduce some of the fluctuations neglected within the BdG approach see the same effect, both for the attractive Hubbard model and a Hamiltonian with $d$-wave pairing symmetry.

arXiv:cond-mat/0507588Physical Review BMar 29, 200637 citations

Pairing in disordered s-wave superconductors and the effect of their coupling

B. Chatterjee, A. Taraphder

arXiv:cond-mat/0702150Solid State CommunicationsSep 25, 20085 citations

Superconductivity and pairing of electrons in three dimensions

Springer eBooksAug 7, 20070 citations

Anti-phase superconducting domain structures in thet-t'-t"-Jmodel

Hiroki Tsuchiura, Masao Ogata

We study spatially modulated d -wave superconducting states in the two-dimensional t-t'-t"-J model within the Bogoliubov-de Gennes theory based on an extended Gutzwiller approximation. We find fully self-consistent solutions involving domain walls with vanishing pairing amplitudes Δ separated by four lattice spacing when the system is about 12.5% hole doping, while five at about 15%. The adjacent superconducting domains are in the anti-phase patterns, that is, the relative phase difference between them is π. The Δ = 0 domain walls involve concentration of mobile holes due to the loss of the condensation energy. We also find that the superconducting coherence peaks at the energy of the d -wave gap in the local densities of states are strongly suppressed in these states with anti-phase superconducting domain structures.We study spatially modulated d -wave superconducting states in the two-dimensional t-t'-t"-J model within the Bogoliubov-de Gennes theory based on an extended Gutzwiller approximation. We find fully self-consistent solutions involving domain walls with vanishing pairing amplitudes Δ separated by four lattice spacing when the system is about 12.5% hole doping, while five at about 15%. The adjacent superconducting domains are in the anti-phase patterns, that is, the relative phase difference between them is π. The Δ = 0 domain walls involve concentration of mobile holes due to the loss of the condensation energy. We also find that the superconducting coherence peaks at the energy of the d -wave gap in the local densities of states are strongly suppressed in these states with anti-phase superconducting domain structures.

Journal of Physics Conference SeriesMar 1, 20092 citations

s -wave superconductivity phase diagram in the inhomogeneous two-dimensional attractive Hubbard model

Karan Aryanpour, Thereza Paiva, Warren E. Pickett +1 more

We study $s$ -wave superconductivity in the two-dimensional square-lattice attractive Hubbard Hamiltonian for various inhomogeneous patterns of interacting sites. Using the Bogoliubov--de Gennes mean-field approximation, we obtain the phase diagram for inhomogeneous patterns in which the on-site attractive interaction ${U}_{i}$ between the electrons takes on two values ${U}_{i}=0$ and $\ensuremath{-}U∕(1\ensuremath{-}f)$ (with $f$ the concentration of noninteracting sites) as a function of average electron occupation per site, $n$ , and study the evolution of the phase diagram as $f$ varies. In certain regions of the phase diagram, inhomogeneity results in a larger zero-temperature average pairing amplitude (order parameter) and also a higher superconducting critical temperature ${T}_{c}$ , relative to a uniform system with the same mean interaction strength (${U}_{i}=\ensuremath{-}U$ on all sites). These effects are observed for stripes, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. The phase diagrams also include regions where superconductivity is obliterated due to the formation of various charge-ordered phases. The enhancement of ${T}_{c}$ due to inhomogeneity is robust as long as the electron doping per site, $n$ , is less than twice the fraction of interacting sites $[2(1\ensuremath{-}f)]$ regardless of the pattern. We also show that for certain inhomogeneous patterns, when $n=2(1\ensuremath{-}f)$, increasing temperature can work against the stability of existing charge-ordered phases for large $f$ and, as a result, enhance ${T}_{c}$ .We study $s$-wave superconductivity in the two-dimensional square-lattice attractive Hubbard Hamiltonian for various inhomogeneous patterns of interacting sites. Using the Bogoliubov--de Gennes mean-field approximation, we obtain the phase diagram for inhomogeneous patterns in which the on-site attractive interaction ${U}_{i}$ between the electrons takes on two values ${U}_{i}=0$ and $\ensuremath{-}U∕(1\ensuremath{-}f)$ (with $f$ the concentration of noninteracting sites) as a function of average electron occupation per site, $n$, and study the evolution of the phase diagram as $f$ varies. In certain regions of the phase diagram, inhomogeneity results in a larger zero-temperature average pairing amplitude (order parameter) and also a higher superconducting critical temperature ${T}_{c}$, relative to a uniform system with the same mean interaction strength (${U}_{i}=\ensuremath{-}U$ on all sites). These effects are observed for stripes, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. The phase diagrams also include regions where superconductivity is obliterated due to the formation of various charge-ordered phases. The enhancement of ${T}_{c}$ due to inhomogeneity is robust as long as the electron doping per site, $n$, is less than twice the fraction of interacting sites $[2(1\ensuremath{-}f)]$ regardless of the pattern. We also show that for certain inhomogeneous patterns, when $n=2(1\ensuremath{-}f)$, increasing temperature can work against the stability of existing charge-ordered phases for large $f$ and, as a result, enhance ${T}_{c}$.

arXiv:0708.0451Physical Review BNov 30, 200723 citations

Fermion Pairing and Superconductivity

Philippe A. Martin, FRANÇOIS ROTHEN

Springer eBooksJan 1, 20020 citations

Inhomogeneous

s

-wave superconductivity is studied in the two-dimensional, square lattice attractive Hubbard Hamiltonian using the Bogoliubov-de Gennes (BdG) mean field approximation. We find that at weak coupling, and for densities mainly below half-filling, an inhomogeneous interaction in which the on-site interaction

{U}_{i}

takes on two values,

{U}_{i}=0,\phantom{\rule{0.3em}{0ex}}2U

results in a larger zero temperature pairing amplitude, and that the superconducting

{T}_{c}

can also be significantly increased, relative to a uniform system with

{U}_{i}=U

on all sites. These effects are observed for stripe, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. Monte Carlo calculations which reintroduce some of the fluctuations neglected within the BdG approach see the same effect, both for the attractive Hubbard model and a Hamiltonian with

d

-wave pairing symmetry.

We study

s

-wave superconductivity in the two-dimensional square-lattice attractive Hubbard Hamiltonian for various inhomogeneous patterns of interacting sites. Using the Bogoliubov--de Gennes mean-field approximation, we obtain the phase diagram for inhomogeneous patterns in which the on-site attractive interaction

{U}_{i}

between the electrons takes on two values

{U}_{i}=0

and $\ensuremath{-}U∕(1\ensuremath{-}f)$ (with

f

the concentration of noninteracting sites) as a function of average electron occupation per site,

n

, and study the evolution of the phase diagram as

f

varies. In certain regions of the phase diagram, inhomogeneity results in a larger zero-temperature average pairing amplitude (order parameter) and also a higher superconducting critical temperature

{T}_{c}

, relative to a uniform system with the same mean interaction strength (${U}_{i}=\ensuremath{-}U$ on all sites). These effects are observed for stripes, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. The phase diagrams also include regions where superconductivity is obliterated due to the formation of various charge-ordered phases. The enhancement of

{T}_{c}

due to inhomogeneity is robust as long as the electron doping per site,

n

, is less than twice the fraction of interacting sites $[2(1\ensuremath{-}f)]$ regardless of the pattern. We also show that for certain inhomogeneous patterns, when $n=2(1\ensuremath{-}f)$, increasing temperature can work against the stability of existing charge-ordered phases for large

f

and, as a result, enhance

{T}_{c}