Stabilization of -wave superconductivity through arsenic -orbital hybridization in electron-doped
In this paper, using random-phase approximation spin-fluctuation theory, we study the influence of the hybridization between iron $d$ orbitals and pnictide $p$ orbitals on the superconducting pairing state in iron-based superconductors. The calculations are performed for a 16-orbital Hubbard-Hund tight-binding model of $${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$$ that includes the As-$p$ orbital degrees of freedom in addition to the Fe-$d$ orbitals and compared to calculations for a 10-orbital Fe-$d$ only model. In both models we find a leading $${s}^{±{}}$$ pairing state and a subleading $${d}_{{x}^{2}{-}{y}^{2}}$$-wave state in the parent compound. Upon doping, we find that the $${s}^{±{}}$$ state remains the leading state in the 16-orbital model up to a doping level of 0.475 electrons per unit cell, at which the hole Fermi-surface pockets at the zone center start to disappear. This is in contrast to the 10-orbital model, where the $d$-wave state becomes the leading state at a doping of less than 0.2 electrons. This improved stability of $${s}^{±{}}$$ pairing is found to arise from a decrease of $${d}_{xy}$$ orbital weight on the electron pockets due to hybridization with the As-$p$ orbitals and the resulting reduction of near $$({\pi},{\pi})$$ spin-fluctuation scattering which favors the competing $d$-wave state. Finally, these results show that the orbital dependent hybridization of Fermi-surface Bloch states with the usually neglected $p$-orbital states is an important ingredient in an improved itinerant pairing theory.
- Authors:
-
[1]
; [2]
; [2]
- Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences. Computational Sciences and Engineering Division
- Publication Date:
- Grant/Contract Number:
- AC05-00OR22725; DMR-1308603
- Type:
- Accepted Manuscript
- Journal Name:
- Physical Review B
- Additional Journal Information:
- Journal Volume: 98; Journal Issue: 2; Journal ID: ISSN 2469-9950
- Publisher:
- American Physical Society (APS)
- Research Org:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice Univ., Houston, TX (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Fermi surface; pairing mechanisms; spin fluctuations; superconductivity; pnictides; random phase approximation; tight-binding model
- OSTI Identifier:
- 1468135
- Alternate Identifier(s):
- OSTI ID: 1460020
Tam, David W., Berlijn, Tom, and Maier, Thomas A.. Stabilization of s -wave superconductivity through arsenic p -orbital hybridization in electron-doped BaFe2As2. United States: N. p.,
Web. doi:10.1103/PhysRevB.98.024507.
Tam, David W., Berlijn, Tom, & Maier, Thomas A.. Stabilization of s -wave superconductivity through arsenic p -orbital hybridization in electron-doped BaFe2As2. United States. doi:10.1103/PhysRevB.98.024507.
Tam, David W., Berlijn, Tom, and Maier, Thomas A.. 2018.
"Stabilization of s -wave superconductivity through arsenic p -orbital hybridization in electron-doped BaFe2As2". United States.
doi:10.1103/PhysRevB.98.024507.
@article{osti_1468135,
title = {Stabilization of s -wave superconductivity through arsenic p -orbital hybridization in electron-doped BaFe2As2},
author = {Tam, David W. and Berlijn, Tom and Maier, Thomas A.},
abstractNote = {In this paper, using random-phase approximation spin-fluctuation theory, we study the influence of the hybridization between iron $d$ orbitals and pnictide $p$ orbitals on the superconducting pairing state in iron-based superconductors. The calculations are performed for a 16-orbital Hubbard-Hund tight-binding model of ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$ that includes the As-$p$ orbital degrees of freedom in addition to the Fe-$d$ orbitals and compared to calculations for a 10-orbital Fe-$d$ only model. In both models we find a leading ${s}^{±{}}$ pairing state and a subleading ${d}_{{x}^{2}{-}{y}^{2}}$-wave state in the parent compound. Upon doping, we find that the ${s}^{±{}}$ state remains the leading state in the 16-orbital model up to a doping level of 0.475 electrons per unit cell, at which the hole Fermi-surface pockets at the zone center start to disappear. This is in contrast to the 10-orbital model, where the $d$-wave state becomes the leading state at a doping of less than 0.2 electrons. This improved stability of ${s}^{±{}}$ pairing is found to arise from a decrease of ${d}_{xy}$ orbital weight on the electron pockets due to hybridization with the As-$p$ orbitals and the resulting reduction of near $({\pi},{\pi})$ spin-fluctuation scattering which favors the competing $d$-wave state. Finally, these results show that the orbital dependent hybridization of Fermi-surface Bloch states with the usually neglected $p$-orbital states is an important ingredient in an improved itinerant pairing theory.},
doi = {10.1103/PhysRevB.98.024507},
journal = {Physical Review B},
number = 2,
volume = 98,
place = {United States},
year = {2018},
month = {7}
}