W=0 pairing in Hubbard and related models of low-dimensional superconductors
(2004) In Journal of Physics: Condensed Matter 16(47). p.1387-1422- Abstract
- Lattice Hamiltonians with on-site interaction W have W = 0 solutions, that is, many-body singlet eigenstates without double occupation. In particular, W = 0 pairs give a clue to understand the pairing force in repulsive Hubbard models. These eigenstates are found in systems with high enough symmetry, like the square, hexagonal or triangular lattices. By a general theorem, we propose a systematic way to construct all the W = 0 pairs of a given Hamiltonian. We also introduce a canonical transformation to calculate the effective interaction between the particles of such pairs. In geometries appropriate for the CuO2 planes of cuprate superconductors, armchair carbon nanotubes, or cobalt oxide planes, the dressed pair becomes a bound state in a... (More)
- Lattice Hamiltonians with on-site interaction W have W = 0 solutions, that is, many-body singlet eigenstates without double occupation. In particular, W = 0 pairs give a clue to understand the pairing force in repulsive Hubbard models. These eigenstates are found in systems with high enough symmetry, like the square, hexagonal or triangular lattices. By a general theorem, we propose a systematic way to construct all the W = 0 pairs of a given Hamiltonian. We also introduce a canonical transformation to calculate the effective interaction between the particles of such pairs. In geometries appropriate for the CuO2 planes of cuprate superconductors, armchair carbon nanotubes, or cobalt oxide planes, the dressed pair becomes a bound state in a physically relevant range of parameters. We also show that W = 0 pairs quantize the magnetic flux as superconducting pairs do. The pairing mechanism breaks down in the presence of strong distortions. The W = 0 pairs are also the building blocks for the antiferromagnetic ground state of the half-filled Hubbard model at weak coupling. Our analytical results for the 4 x 4 Hubbard square lattice, compared to available numerical data, demonstrate that the method, besides providing an intuitive grasp on pairing, also has quantitative predictive power. We also consider including phonon effects in this scenario. Preliminary calculations with small clusters indicate that vector phonons hinder pairing while half-breathing modes are synergic with the W = 0 pairing mechanism both at weak coupling and in the polaronic regime. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/258358
- author
- Balzarotti, A ; Cini, M ; Perfetto, E and Stefanucci, Gianluca LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physics: Condensed Matter
- volume
- 16
- issue
- 47
- pages
- 1387 - 1422
- publisher
- IOP Publishing
- external identifiers
-
- wos:000225796800001
- scopus:10344245529
- ISSN
- 1361-648X
- DOI
- 10.1088/0953-8984/16/47/R01
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Mathematical Physics (Faculty of Technology) (011040002), Department of Physics (011013000)
- id
- 95c75785-ce10-48e7-b58f-93ab13840614 (old id 258358)
- date added to LUP
- 2016-04-01 17:03:22
- date last changed
- 2022-01-29 00:01:04
@article{95c75785-ce10-48e7-b58f-93ab13840614,
abstract = {{Lattice Hamiltonians with on-site interaction W have W = 0 solutions, that is, many-body singlet eigenstates without double occupation. In particular, W = 0 pairs give a clue to understand the pairing force in repulsive Hubbard models. These eigenstates are found in systems with high enough symmetry, like the square, hexagonal or triangular lattices. By a general theorem, we propose a systematic way to construct all the W = 0 pairs of a given Hamiltonian. We also introduce a canonical transformation to calculate the effective interaction between the particles of such pairs. In geometries appropriate for the CuO2 planes of cuprate superconductors, armchair carbon nanotubes, or cobalt oxide planes, the dressed pair becomes a bound state in a physically relevant range of parameters. We also show that W = 0 pairs quantize the magnetic flux as superconducting pairs do. The pairing mechanism breaks down in the presence of strong distortions. The W = 0 pairs are also the building blocks for the antiferromagnetic ground state of the half-filled Hubbard model at weak coupling. Our analytical results for the 4 x 4 Hubbard square lattice, compared to available numerical data, demonstrate that the method, besides providing an intuitive grasp on pairing, also has quantitative predictive power. We also consider including phonon effects in this scenario. Preliminary calculations with small clusters indicate that vector phonons hinder pairing while half-breathing modes are synergic with the W = 0 pairing mechanism both at weak coupling and in the polaronic regime.}},
author = {{Balzarotti, A and Cini, M and Perfetto, E and Stefanucci, Gianluca}},
issn = {{1361-648X}},
language = {{eng}},
number = {{47}},
pages = {{1387--1422}},
publisher = {{IOP Publishing}},
series = {{Journal of Physics: Condensed Matter}},
title = {{W=0 pairing in Hubbard and related models of low-dimensional superconductors}},
url = {{http://dx.doi.org/10.1088/0953-8984/16/47/R01}},
doi = {{10.1088/0953-8984/16/47/R01}},
volume = {{16}},
year = {{2004}},
}