A Bogoliubov-de Gennes study of d-wave Hubbard superconductors under magnetic field

• Published in: Physica. B, Condensed matter Vol. 553; pp. 36 - 39
• Main Authors: Galván, César G., Pérez, Luis A., Wang, Chumin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2019; Elsevier BV
• Subjects: Bogoliubov-de Gennes formalism; Carrier density; d-wave superconductivity; Electrons; Generalized Hubbard model; Magnetic fields; Magnetic vortices; Photoelectric emission; Specific heat; Superconductivity; Superconductors; Temperature dependence; Thermodynamic models; Bogoliubov-de Gennes formalism; d-wave superconductivity; Magnetic vortices; Specific heat; Generalized Hubbard model
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2018.08.054

The formation of magnetic vortices and their effects on the electronic specific heat (Cel) of d-wave superconductors are studied within the generalized Hubbard model and the Bogoliubov-de Gennes (BdG) formalism. The BdG equations provide the local superconducting gaps as a function of the electron-electron interaction and carrier concentration. The electron hopping parameters of the generalized Hubbard model for the ceramic superconductor La2-xSrxCuO4 are determined by using angle-resolved photoemission spectroscopy (ARPES) data. The BdG results show that the d-wave superconducting states, induced by the correlated hopping interactions, possess an upper-critical-magnetic-field temperature dependence consistent with the generalized Ginzburg-Landau model for type II superconductors. Furthermore, the electronic specific heat reveals a square-power-law temperature behavior observed in d-wave superconductors. When an external magnetic field is applied, such behavior becomes linear at the low-temperature limit. The coefficient of this linear behavior confirms the square-root dependence with the external magnetic field predicted by the Volovik thermodynamic model and its trend is consistent with experimental data obtained from La1.85Sr0.15CuO4. •A quantum-mechanical study of d-wave superconductors under an external magnetic field is reported.•An approach that combines a generalized Hubbard model and the Bogoliubov-de Gennes formalism is proposed.•The temperature dependence of the upper critical magnetic field agrees with the generalized Ginzburg-Landau model.•The specific heat results obtained are consistent with experimental data of La1.85Sr0.15CuO4.