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Fermi-surface-free superconductivity in underdoped (Bi,Pb)(Sr,La)2CuO(6+δ) (Bi2201).

Mistark P, Hafiz H, Markiewicz RS, Bansil A - Sci Rep (2015)

Bottom Line: Fermi-surface-free superconductivity arises when the superconducting order pulls down spectral weight from a band that is completely above the Fermi energy in the normal state.The change in Fermi surface topology is accompanied by a characteristic rise in the spectral weight.Our results support the presence of a trisected superconducting dome, and suggest that superconductivity is responsible for stabilizing the (π,π) magnetic order at higher doping.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Northeastern University, Boston.

ABSTRACT
Fermi-surface-free superconductivity arises when the superconducting order pulls down spectral weight from a band that is completely above the Fermi energy in the normal state. We show that this can arise in hole-doped cuprates when a competing order causes a reconstruction of the Fermi surface. The change in Fermi surface topology is accompanied by a characteristic rise in the spectral weight. Our results support the presence of a trisected superconducting dome, and suggest that superconductivity is responsible for stabilizing the (π,π) magnetic order at higher doping.

No MeSH data available.


Related in: MedlinePlus

Doping dependence of order parameters and the corresponding potentials.(a) Self-consistent values of ΔAF as a function of doping for a system with AF order only (gray) or with combined SC + AF order (blue). The red curve shows the SC gap with the scale on the right hand vertical axis. The black dashed line indicates TT1 for our model at xLDA = 0.138. (b) U/t fit (blue curve) to the results from Ref. 3 (green circles) as a function of doping and V/t (red curve) calculated with equation (5) from the assumed SC dome. For the present analysis we are only interested in dopings greater than x = 0.05, where the fit is quite good. The orange and light blue dashed curves in (a) and (b) represent the same quantities as their red and blue, solid lined counterparts, respectively, except that the doping dependence of V is assumed linear and ΔSC and S are calculated using Eqs. 5 and 6. This shows that a large potential V is needed for SC order to be sustained to dopings well below the TT1.
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f4: Doping dependence of order parameters and the corresponding potentials.(a) Self-consistent values of ΔAF as a function of doping for a system with AF order only (gray) or with combined SC + AF order (blue). The red curve shows the SC gap with the scale on the right hand vertical axis. The black dashed line indicates TT1 for our model at xLDA = 0.138. (b) U/t fit (blue curve) to the results from Ref. 3 (green circles) as a function of doping and V/t (red curve) calculated with equation (5) from the assumed SC dome. For the present analysis we are only interested in dopings greater than x = 0.05, where the fit is quite good. The orange and light blue dashed curves in (a) and (b) represent the same quantities as their red and blue, solid lined counterparts, respectively, except that the doping dependence of V is assumed linear and ΔSC and S are calculated using Eqs. 5 and 6. This shows that a large potential V is needed for SC order to be sustained to dopings well below the TT1.

Mentions: It is interesting to examine how TT1 modifies other properties of the cuprates, leading to possible experimental signatures. Figure 4(a) shows that the self-consistent ΔAF drops sharply across the transition (vertical dashed line) as the electron pocket opens up. Note that in order to reproduce the experimental SC dome in the low-doping regime, the interaction parameter V in Fig. 4(b) must increase rapidly with underdoping below TT1. While a strong increase of the pairing potential near half-filling has been predicted29, the dashed line in Fig. 4(b) indicates the effects of a more modest increase in V. TC now decreases very rapidly below the TT1, Fig. 4(a), but there is still a range of FS-free SC in Fig. 2(c). To explain the lower part of the experimental SC dome in this scenario, we would have to postulate that the uniform AF + SC phase becomes unstable to nanoscale phase separation (NPS)303132, which is sensitive to impurities. It could thus lead to the observed low-energy spin-glass phase and to the opening of an additional nodal gap31. Termination of this NPS at TT1 suggests that at this doping SC order stabilizes the associated (π,π) AF order.


Fermi-surface-free superconductivity in underdoped (Bi,Pb)(Sr,La)2CuO(6+δ) (Bi2201).

Mistark P, Hafiz H, Markiewicz RS, Bansil A - Sci Rep (2015)

Doping dependence of order parameters and the corresponding potentials.(a) Self-consistent values of ΔAF as a function of doping for a system with AF order only (gray) or with combined SC + AF order (blue). The red curve shows the SC gap with the scale on the right hand vertical axis. The black dashed line indicates TT1 for our model at xLDA = 0.138. (b) U/t fit (blue curve) to the results from Ref. 3 (green circles) as a function of doping and V/t (red curve) calculated with equation (5) from the assumed SC dome. For the present analysis we are only interested in dopings greater than x = 0.05, where the fit is quite good. The orange and light blue dashed curves in (a) and (b) represent the same quantities as their red and blue, solid lined counterparts, respectively, except that the doping dependence of V is assumed linear and ΔSC and S are calculated using Eqs. 5 and 6. This shows that a large potential V is needed for SC order to be sustained to dopings well below the TT1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4471721&req=5

f4: Doping dependence of order parameters and the corresponding potentials.(a) Self-consistent values of ΔAF as a function of doping for a system with AF order only (gray) or with combined SC + AF order (blue). The red curve shows the SC gap with the scale on the right hand vertical axis. The black dashed line indicates TT1 for our model at xLDA = 0.138. (b) U/t fit (blue curve) to the results from Ref. 3 (green circles) as a function of doping and V/t (red curve) calculated with equation (5) from the assumed SC dome. For the present analysis we are only interested in dopings greater than x = 0.05, where the fit is quite good. The orange and light blue dashed curves in (a) and (b) represent the same quantities as their red and blue, solid lined counterparts, respectively, except that the doping dependence of V is assumed linear and ΔSC and S are calculated using Eqs. 5 and 6. This shows that a large potential V is needed for SC order to be sustained to dopings well below the TT1.
Mentions: It is interesting to examine how TT1 modifies other properties of the cuprates, leading to possible experimental signatures. Figure 4(a) shows that the self-consistent ΔAF drops sharply across the transition (vertical dashed line) as the electron pocket opens up. Note that in order to reproduce the experimental SC dome in the low-doping regime, the interaction parameter V in Fig. 4(b) must increase rapidly with underdoping below TT1. While a strong increase of the pairing potential near half-filling has been predicted29, the dashed line in Fig. 4(b) indicates the effects of a more modest increase in V. TC now decreases very rapidly below the TT1, Fig. 4(a), but there is still a range of FS-free SC in Fig. 2(c). To explain the lower part of the experimental SC dome in this scenario, we would have to postulate that the uniform AF + SC phase becomes unstable to nanoscale phase separation (NPS)303132, which is sensitive to impurities. It could thus lead to the observed low-energy spin-glass phase and to the opening of an additional nodal gap31. Termination of this NPS at TT1 suggests that at this doping SC order stabilizes the associated (π,π) AF order.

Bottom Line: Fermi-surface-free superconductivity arises when the superconducting order pulls down spectral weight from a band that is completely above the Fermi energy in the normal state.The change in Fermi surface topology is accompanied by a characteristic rise in the spectral weight.Our results support the presence of a trisected superconducting dome, and suggest that superconductivity is responsible for stabilizing the (π,π) magnetic order at higher doping.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Northeastern University, Boston.

ABSTRACT
Fermi-surface-free superconductivity arises when the superconducting order pulls down spectral weight from a band that is completely above the Fermi energy in the normal state. We show that this can arise in hole-doped cuprates when a competing order causes a reconstruction of the Fermi surface. The change in Fermi surface topology is accompanied by a characteristic rise in the spectral weight. Our results support the presence of a trisected superconducting dome, and suggest that superconductivity is responsible for stabilizing the (π,π) magnetic order at higher doping.

No MeSH data available.


Related in: MedlinePlus