Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice
We study the phase diagram of the extended Hubbard model on a two-dimensional square lattice, including on-site (U) and nearest-neighbor (V) interactions, at weak couplings. We show that the charge-density wave phase that is known to occur at half filling when 4V>U gives way to a dxy-wave superco...
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ftcdlib:qt6zs78605 2023-05-15T16:55:49+02:00 Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice Huang, WM Lai, CY Shi, C Tsai, SW 2013-08-12 application/pdf http://www.escholarship.org/uc/item/6zs78605 english eng eScholarship, University of California qt6zs78605 http://www.escholarship.org/uc/item/6zs78605 public Huang, WM; Lai, CY; Shi, C; & Tsai, SW. (2013). Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice. Physical Review B - Condensed Matter and Materials Physics, 88(5). doi:10.1103/PhysRevB.88.054504. UC Riverside: Retrieved from: http://www.escholarship.org/uc/item/6zs78605 article 2013 ftcdlib https://doi.org/10.1103/PhysRevB.88.054504 2018-09-28T22:51:47Z We study the phase diagram of the extended Hubbard model on a two-dimensional square lattice, including on-site (U) and nearest-neighbor (V) interactions, at weak couplings. We show that the charge-density wave phase that is known to occur at half filling when 4V>U gives way to a dxy-wave superconducting instability away from half filling, when the Fermi surface is not perfectly nested, and for sufficiently large repulsive V and a range of on-site repulsive interaction U. In addition, when nesting is further suppressed and in the presence of a nearest-neighbor attraction, a triplet time-reversal breaking (px+ipy)-wave pairing instability emerges, competing with the dx2-y2pairing state that is known to dominate at fillings just slightly away from half. At even smaller fillings, where the Fermi surface no longer presents any nesting, the (px+ipy)-wave superconducting phase dominates in the whole regime of on-site repulsions and nearest-neighbor attractions, while dxypairing occurs in the presence of on-site attraction. Our results suggest that zero-energy Majorana fermions can be realized on a square lattice in the presence of a magnetic field. For a system of cold fermionic atoms on a two-dimensional square optical lattice, both an on-site repulsion and a nearest-neighbor attraction would be required, in addition to rotation of the system to create vortices. We discuss possible ways of experimentally engineering the required interaction terms in a cold atom system. © 2013 American Physical Society. Article in Journal/Newspaper IPY University of California: eScholarship Physical Review B 88 5 |
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University of California: eScholarship |
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English |
description |
We study the phase diagram of the extended Hubbard model on a two-dimensional square lattice, including on-site (U) and nearest-neighbor (V) interactions, at weak couplings. We show that the charge-density wave phase that is known to occur at half filling when 4V>U gives way to a dxy-wave superconducting instability away from half filling, when the Fermi surface is not perfectly nested, and for sufficiently large repulsive V and a range of on-site repulsive interaction U. In addition, when nesting is further suppressed and in the presence of a nearest-neighbor attraction, a triplet time-reversal breaking (px+ipy)-wave pairing instability emerges, competing with the dx2-y2pairing state that is known to dominate at fillings just slightly away from half. At even smaller fillings, where the Fermi surface no longer presents any nesting, the (px+ipy)-wave superconducting phase dominates in the whole regime of on-site repulsions and nearest-neighbor attractions, while dxypairing occurs in the presence of on-site attraction. Our results suggest that zero-energy Majorana fermions can be realized on a square lattice in the presence of a magnetic field. For a system of cold fermionic atoms on a two-dimensional square optical lattice, both an on-site repulsion and a nearest-neighbor attraction would be required, in addition to rotation of the system to create vortices. We discuss possible ways of experimentally engineering the required interaction terms in a cold atom system. © 2013 American Physical Society. |
format |
Article in Journal/Newspaper |
author |
Huang, WM Lai, CY Shi, C Tsai, SW |
spellingShingle |
Huang, WM Lai, CY Shi, C Tsai, SW Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
author_facet |
Huang, WM Lai, CY Shi, C Tsai, SW |
author_sort |
Huang, WM |
title |
Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
title_short |
Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
title_full |
Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
title_fullStr |
Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
title_full_unstemmed |
Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice |
title_sort |
unconventional superconducting phases for the two-dimensional extended hubbard model on a square lattice |
publisher |
eScholarship, University of California |
publishDate |
2013 |
url |
http://www.escholarship.org/uc/item/6zs78605 |
genre |
IPY |
genre_facet |
IPY |
op_source |
Huang, WM; Lai, CY; Shi, C; & Tsai, SW. (2013). Unconventional superconducting phases for the two-dimensional extended Hubbard model on a square lattice. Physical Review B - Condensed Matter and Materials Physics, 88(5). doi:10.1103/PhysRevB.88.054504. UC Riverside: Retrieved from: http://www.escholarship.org/uc/item/6zs78605 |
op_relation |
qt6zs78605 http://www.escholarship.org/uc/item/6zs78605 |
op_rights |
public |
op_doi |
https://doi.org/10.1103/PhysRevB.88.054504 |
container_title |
Physical Review B |
container_volume |
88 |
container_issue |
5 |
_version_ |
1766046878464475136 |