Coulomb problem in iron-based superconductors

König, Elio J.; Coleman, Piers

doi:10.1103/physrevb.99.144522

Cited by 8 publications

(4 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 1 estimates the error of the theoretical Tc by tuning μ*. Despite the calculation of μ* as a function of Debye temperature and Fermi level [42] may not be very accurate in such a strongly correlated electron system [43], it has been argued that for the most Fe-based superconductors μ* should be 0.15-0.2 [44]. The error of our Tc calculation due to the uncertainty of μ * is within ~15%.…”

Section: Resultsmentioning

confidence: 91%

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Wong¹,

Lortz²

2023

Preprint

View full text Add to dashboard Cite

Many theoretical models of iron-based superconductors have been proposed but Tc calculations based on the models are usually missing. We have chosen two models of iron-based superconductors in the literature and then compute the Tc values accordingly: Recently two models have been announced which suggest that superconducting electron concentration involved in the pairing mechanism of iron-based superconductors may have been underestimated, and that the antiferromagnetism and the induced xy potential may even have a dramatic amplification effect on electron-phonon coupling. We use bulk FeSe, LiFeAs and NaFeAs data to calculate the Tc based on these models and test if the combined model can predict the superconducting transition temperature (Tc) of the nanostructured FeSe monolayer well. To substantiate the recently announced xy potential in the literature, we create a two-channel model to separately superimpose the dynamics of the electron in the upper and lower tetrahedral plane. The results of our two-channel model support the literature data. While scientists are still searching for a universal DFT functional that can describe the pairing mechanism of all iron-based superconductors, we base on the ARPES data to propose an empirical combination of DFT functional for revising the electron-phonon scattering matrix in the superconducting state, which ensures that all electrons involved in iron-based superconductivity are included in the computation. Our computational model takes into account this amplifying effect of antiferromagnetism and the correction of the electron-phonon scattering matrix together with the abnormal soft out-of-plane lattice vibration of the layered structure, which allows us to calculate theoretical Tc values of LiFeAs, NaFeAs and FeSe as a function of pressure that correspond reasonably well to the experimental values. More importantly, by taking into account the interfacial effect between an FeSe monolayer and its SrTiO3 substrate as an additional gain factor, our calculated Tc value is up to 91 K high, and provides evidence that the strong Tc enhancement recently observed in such monolayers with Tc reaching 100 K may be contributed from the electrons within the ARPES range.

show abstract

Section: Resultsmentioning

confidence: 91%

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Wong¹,

Lortz²

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Figure 1 estimates the error of the theoretical T c by tuning μ* . Despite that the calculation of μ* as a function of Debye temperature and Fermi level [ 41 ] may not be very accurate in such a strongly correlated electron system [ 42 ], it has been argued that for the most Fe-based superconductors, μ * should be 0.15–0.2 [ 12 ]. In this paper, we choose the value ( µ * = 0.15) of the Coulomb pseudopotential to calculate the T c of LiFeAs, NaFeAs and FeSe to make a fair comparison.…”

Section: Resultsmentioning

confidence: 99%

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Wong

Lortz

2023

Materials

View full text Add to dashboard Cite

Many theoretical models of iron-based superconductors (IBSC) have been proposed, but the superconducting transition temperature (Tc) calculations based on these models are usually missing. We have chosen two models of iron-based superconductors from the literature and computed the Tc values accordingly; recently two models have been announced which suggest that the superconducting electron concentration involved in the pairing mechanism of iron-based superconductors may have been underestimated and that the antiferromagnetism and the induced xy potential may even have a dramatic amplification effect on electron–phonon coupling. We use bulk FeSe, LiFeAs and NaFeAs data to calculate the Tc based on these models and test if the combined model can predict the superconducting transition temperature (Tc) of the nanostructured FeSe monolayer well. To substantiate the recently announced xy potential in the literature, we create a two-channel model to separately superimpose the dynamics of the electron in the upper and lower tetrahedral plane. The results of our two-channel model support the literature data. While scientists are still searching for a universal DFT functional that can describe the pairing mechanism of all iron-based superconductors, we base our model on the ARPES data to propose an empirical combination of a DFT functional for revising the electron–phonon scattering matrix in the superconducting state, which ensures that all electrons involved in iron-based superconductivity are included in the computation. Our computational model takes into account this amplifying effect of antiferromagnetism and the correction of the electron–phonon scattering matrix, together with the abnormal soft out-of-plane lattice vibration of the layered structure. This allows us to calculate theoretical Tc values of LiFeAs, NaFeAs and FeSe as a function of pressure that correspond reasonably well to the experimental values. More importantly, by taking into account the interfacial effect between an FeSe monolayer and its SrTiO3 substrate as an additional gain factor, our calculated Tc value is up to 91 K and provides evidence that the strong Tc enhancement recently observed in such monolayers with Tc reaching 100 K may be contributed from the electrons within the ARPES range.

show abstract

“…Otherwise, we set

and

. Although the accuracy of calculating the pseudopotential for a strongly correlated electron system, such as Fe-based superconductors, as a function of Debye temperature and Fermi level, 36 may not be very precise, it has been suggested that the value should be approximately 0.15 for most Fe-based superconductors. 36 We put the ab-initio details in the supplemental information .…”

Section: Methodsmentioning

confidence: 99%

Phase diagram simulations incorporating the gap anisotropy with AFM spin and charge density wave under spin-orbital coupling in Fe-based superconductors

Wong,

Lortz

2024

iScience

View full text Add to dashboard Cite

Coulomb problem in iron-based superconductors

Cited by 8 publications

References 60 publications

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Phase diagram simulations incorporating the gap anisotropy with AFM spin and charge density wave under spin-orbital coupling in Fe-based superconductors

Contact Info

Product

Resources

About