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

Influence of long-range interactions on superconductivity and phase separation

Stephan Haas, Elbio R. Dagotto, Alexander Nazarenko

Journal of SuperconductivityOct 1, 19950 citations

Optimal inhomogeneity for superconductivity

Enrico Arrigoni, Steven Allan Kivelson

We study the effect of nonuniform transverse couplings on a quasi-one-dimensional superconductor. We show that inhomogeneous couplings quite generally increase the superconducting (pairing) gap relative to the uniform system, but that beyond an ``optimal'' degree of inhomogeneity, they lead to a suppression of the tendency towards phase coherence. The optimal conditions for superconductivity are derived. We also show that a delocalized, spin-gapped phase is stable against weak disorder in a four-leg ladder with moderate repulsive interactions.We study the effect of nonuniform transverse couplings on a quasi-one-dimensional superconductor. We show that inhomogeneous couplings quite generally increase the superconducting (pairing) gap relative to the uniform system, but that beyond an ``optimal'' degree of inhomogeneity, they lead to a suppression of the tendency towards phase coherence. The optimal conditions for superconductivity are derived. We also show that a delocalized, spin-gapped phase is stable against weak disorder in a four-leg ladder with moderate repulsive interactions.

arXiv:cond-mat/0212256Physical review. B, Condensed matterNov 14, 200336 citations

Transport in partially equilibrated inhomogeneous quantum wires

Alex Levchenko, Tobias Micklitz, Jérôme Rech +1 more

We study transport properties of weakly interacting one-dimensional electron systems including on an equal footing thermal equilibration due to three-particle collisions and the effects of large-scale inhomogeneities. We show that equilibration in an inhomogeneous quantum wire is characterized by the competition of interaction processes which reduce the electrons total momentum and such which change the number of right- and left-moving electrons. We find that the combined effect of interactions and inhomogeneities can dramatically increase the resistance of the wire. In addition, we find that the interactions strongly affect the thermoelectric properties of inhomogeneous wires and calculate their thermal conductance, thermopower, and Peltier coefficient.We study transport properties of weakly interacting one-dimensional electron systems including on an equal footing thermal equilibration due to three-particle collisions and the effects of large-scale inhomogeneities. We show that equilibration in an inhomogeneous quantum wire is characterized by the competition of interaction processes which reduce the electrons total momentum and such which change the number of right- and left-moving electrons. We find that the combined effect of interactions and inhomogeneities can dramatically increase the resistance of the wire. In addition, we find that the interactions strongly affect the thermoelectric properties of inhomogeneous wires and calculate their thermal conductance, thermopower, and Peltier coefficient.

arXiv:1005.0009Physical Review BSep 8, 201027 citations

Induced magnetization and inhomogeneous superconductivity in presence of external magnetic field

Chia‐Wei Yang, ARMEN N. KOCHARIAN, Y. L. Chiang

Physica C SuperconductivityNov 1, 20011 citation

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.