scholarly journals Pairing symmetries in the Zeeman-coupled extended attractive Hubbard model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Swagatam Nayak ◽  
Navketan Batra ◽  
Sanjeev Kumar
Keyword(s):  
Hubbard Model ◽  
Mean Field ◽  
Field Approach ◽  
Hartree Fock ◽  
Average Electron Density ◽  
Pairing Symmetries ◽  
Pairing Correlations ◽  
Attractive Hubbard Model ◽  
Average Electron ◽  
Superconducting Pairing

AbstractBy introducing the possibility of equal- and opposite-spin pairings concurrently, we show that the ground state of the extended attractive Hubbard model (EAHM) exhibits rich phase diagrams with a variety of singlet, triplet, and mixed parity superconducting orders. We study the competition between these superconducting pairing symmetries invoking an unrestricted Hartree–Fock–Bogoliubov–de Gennes (HFBdG) mean-field approach, and we use the d-vector formalism to characterize the nature of the stabilized superconducting orders. We discover that, while all other types of orders are suppressed, a non-unitary triplet order dominates the phase space in the presence of an in-plane external magnetic field. We also find a transition between a non-unitary to unitary superconducting phase driven by the change in average electron density. Our results serve as a reference for identifying and understanding the nature of superconductivity based on the symmetries of the pairing correlations. The results further highlight that EAHM is a suitable effective model for describing most of the pairing symmetries discovered in different materials.

scholarly journals A mean-field approach to Kondo-attractive-Hubbard model

2018 ◽  
Vol 30 (4) ◽  
pp. 045602 ◽  
Author(s):  
Natanael C Costa ◽  
José P de Lima ◽  
Thereza Paiva ◽  
Mohammed El Massalami ◽  
Raimundo R dos Santos
Keyword(s):  
Hubbard Model ◽  
Mean Field ◽  
Field Approach ◽  
Attractive Hubbard Model

THE INNER CRUST OF NEUTRON STARS IN RELATIVISTIC MEAN FIELD APPROACH

2008 ◽  
Vol 17 (09) ◽  
pp. 1765-1773 ◽  
Author(s):  
JIGUANG CAO ◽  
ZHONGYU MA ◽  
NGUYEN VAN GIAI
Keyword(s):  
Boundary Conditions ◽  
Neutron Stars ◽  
Mean Field ◽  
Bcs Theory ◽  
Neutron Density ◽  
Field Approach ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Rmf Model

The microscopic properties and superfluidity of the inner crust in neutron stars are investigated in the framework of the relativistic mean field(RMF) model and BCS theory. The Wigner-Seitz(W-S) cell of inner crust is composed of neutron-rich nuclei immersed in a sea of dilute, homogeneous neutron gas. The pairing properties of nucleons in the W-S cells are treated in BCS theory with Gogny interaction. In this work, we emphasize on the choice of the boundary conditions in the RMF approach and superfluidity of the inner crust. Three kinds of boundary conditions are suggested. The properties of the W-S cells with the three kinds of boundary conditions are investigated. The neutron density distributions in the RMF and Hartree-Fock-Bogoliubov(HFB) models are compared.

scholarly journals Comparison between the Thomas–Fermi and Hartree–Fock–Bogoliubov Methods in the Inner Crust of a Neutron Star: The Role of Pairing Correlations

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 206
Author(s):  
Matthew Shelley ◽  
Alessandro Pastore
Keyword(s):  
Neutron Star ◽  
Mean Field ◽  
Pairing Correlation ◽  
Field Methods ◽  
Density Region ◽  
Thomas Fermi ◽  
Hartree Fock ◽  
Pairing Correlations ◽  
Mean Field Methods

We investigated the role of a pairing correlation in the chemical composition of the inner crust of a neutron star with the extended Thomas–Fermi method, using the Strutinsky integral correction. We compare our results with the fully self-consistent Hartree–Fock–Bogoliubov approach, showing that the resulting discrepancy, apart from the very low density region, is compatible with the typical accuracy we can achieve with standard mean-field methods.

QUASILOCAL DENSITY FUNCTIONAL THEORY FOR NUCLEI INCLUDING PAIRING CORRELATIONS

2007 ◽  
Vol 16 (02) ◽  
pp. 249-262 ◽  
Author(s):  
X. VIÑAS ◽  
V. I. TSELYAEV ◽  
V. B. SOUBBOTIN ◽  
S. KREWALD
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Equations Of Motion ◽  
Mean Field ◽  
Field Operator ◽  
Functional Theory ◽  
Hartree Fock ◽  
Orbit Potential ◽  
The Density Functional Theory ◽  
Pairing Correlations

We propose first a generalization of the Density Functional Theory leading to single-particle equations of motion with a quasilocal mean-field operator containing a position-dependent effective mass and a spin-orbit potential. Ground-state properties of doubly magic nuclei are obtained within this framework using the Gogny D1S force and compared with the exact Hartree-Fock values. Next, extend the Density Functional Theory to include pairing correlations without formal violation of the particle-number condition. This theory, which is nonlocal, is simplified by a suitable quasilocal reduction. Some calculations to show the ability of this theory are presented.

scholarly journals Pairing correlations in the attractive Hubbard model on chains, ladders, and squares

2000 ◽  
Vol 62 (1) ◽  
pp. 600-614 ◽  
Author(s):  
M. Guerrero ◽  
G. Ortiz ◽  
J. E. Gubernatis
Keyword(s):  
Hubbard Model ◽  
Pairing Correlations ◽  
Attractive Hubbard Model
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