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Temperature-Dependent s_{±} ↔ s_{++} Transitions in the Multiband Model for Fe-Based Superconductors with Impurities

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## Abstract

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## 1. Introduction

## 2. Model and Method

## 3. Results and Discussion

## 4. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Abbreviations

FeBS | Fe-based superconductors |

NMR | nuclear magnetic resonance |

## References

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**Figure 1.**Dependence of the lowest-frequency Matsubara gap function ${\Delta}_{b,n=0}$, indicated by the color code, for the band b on the scattering rate ${\Gamma}_{a}$ and the temperature T in the Born limit, $\sigma =0.0$. All quantities are normalized by ${T}_{c0}$. Green color marks the state with the vanishingly small gap, ${\Delta}_{b,n}<{10}^{-3}{T}_{c0}$.

**Figure 2.**Dependence of the lowest-frequency Matsubara gap function ${\Delta}_{b,n=0}$, indicated by the color code, for the band b on ${\Gamma}_{a}$ and T in the intermediate scattering limit, $\sigma =0.5$. All quantities are normalized by ${T}_{c0}$. Green color marks the state with the vanishingly small gap, ${\Delta}_{b,n}<{10}^{-3}{T}_{c0}$.

**Figure 3.**Temperature dependence of the lowest-frequency Matsubara gap ${\Delta}_{\alpha ,n=0}$ normalized by ${T}_{c0}$ for fixed values of ${\Gamma}_{a}$ in the Born limit with the band index (

**a**) $\alpha =a$ and (

**b**) $\alpha =b$.

**Figure 4.**Temperature dependence of the lowest-frequency Matsubara order parameter ${\tilde{\varphi}}_{\alpha ,n=0}$ (

**a**,

**c**) and the renormalization factor ${Z}_{\alpha ,n=0}$ (

**b**,

**d**), both normalized by ${T}_{c0}$, for fixed values of ${\Gamma}_{a}$ in the Born limit with the band index $\alpha =a$ (

**a**,

**b**) and $\alpha =b$ (

**c**,

**d**).

**Figure 5.**Temperature dependence of the lowest-frequency Matsubara gap ${\Delta}_{\alpha ,n=0}$ normalized by ${T}_{c0}$ for fixed values of ${\Gamma}_{a}$ in the intermediate scattering limit ($\sigma =0.5$) with the band index (

**a**) $\alpha =a$ and (

**b**) $\alpha =b$.

**Figure 6.**Temperature dependence of the lowest-frequency Matsubara order parameter ${\tilde{\varphi}}_{\alpha ,n=0}$ (

**a**,

**c**) and the renormalization factor ${Z}_{\alpha ,n=0}$ (

**b**,

**d**), both normalized by ${T}_{c0}$, for fixed values of ${\Gamma}_{a}$ in the intermediate scattering limit ($\sigma =0.5$) with the band index $\alpha =a$ (

**a**,

**b**) and $\alpha =b$ (

**c**,

**d**).

**Figure 7.**Temperature dependence of the gap for higher Matsubara frequencies, (

**a**) ${\Delta}_{\alpha ,n=1}$ and (

**b**) ${\Delta}_{\alpha ,n=10}$, normalized by ${T}_{c0}$ for fixed values of ${\Gamma}_{a}$ in the intermediate scattering limit ($\sigma =0.5$). Gaps corresponding to the band index a (band index b) are shown by dashed (solid) curves.

**Figure 8.**Temperature dependencies of lowest-frequency Matsubara gap ${\Delta}_{b,n=0}$ normalized by ${T}_{c0}$ in the Born limit for several values of ${\Gamma}_{a}$. Solid curves correspond to a smooth evolution of the gap in the ${s}_{\pm}$ state and across the ${s}_{++}\to {s}_{\pm}$ transition, while the temperature dependencies with the discontinuous jump of the gap are shown by symbols.

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**MDPI and ACS Style**

Shestakov, V.A.; Korshunov, M.M.; Dolgov, O.V.
Temperature-Dependent *s*_{±} ↔ *s*_{++} Transitions in the Multiband Model for Fe-Based Superconductors with Impurities. *Symmetry* **2018**, *10*, 323.
https://doi.org/10.3390/sym10080323

**AMA Style**

Shestakov VA, Korshunov MM, Dolgov OV.
Temperature-Dependent *s*_{±} ↔ *s*_{++} Transitions in the Multiband Model for Fe-Based Superconductors with Impurities. *Symmetry*. 2018; 10(8):323.
https://doi.org/10.3390/sym10080323

**Chicago/Turabian Style**

Shestakov, V. A., M. M. Korshunov, and O. V. Dolgov.
2018. "Temperature-Dependent *s*_{±} ↔ *s*_{++} Transitions in the Multiband Model for Fe-Based Superconductors with Impurities" *Symmetry* 10, no. 8: 323.
https://doi.org/10.3390/sym10080323