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Possible superconductivity in Sr₂IrO₄ probed by quasiparticle interference.

Gao Y, Zhou T, Huang H, Wang QH - Sci Rep (2015)

Bottom Line: Based on the possible superconducting (SC) pairing symmetries recently proposed, the quasiparticle interference (QPI) patterns in electron- and hole-doped Sr₂IrO₄ are theoretically investigated.In the electron-doped case, the QPI spectra can be explained based on a model similar to the octet model of the cuprates while in the hole-doped case, both the Fermi surface topology and the sign of the SC order parameter resemble those of the iron pnictides and there exists a QPI vector resulting from the interpocket scattering between the electron and hole pockets.In both cases, the evolution of the QPI vectors with energy and their behaviors in the nonmagnetic and magnetic impurity scattering cases can well be explained based on the evolution of the constant-energy contours and the sign structure of the SC order parameter.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing. 210023, China.

ABSTRACT
Based on the possible superconducting (SC) pairing symmetries recently proposed, the quasiparticle interference (QPI) patterns in electron- and hole-doped Sr₂IrO₄ are theoretically investigated. In the electron-doped case, the QPI spectra can be explained based on a model similar to the octet model of the cuprates while in the hole-doped case, both the Fermi surface topology and the sign of the SC order parameter resemble those of the iron pnictides and there exists a QPI vector resulting from the interpocket scattering between the electron and hole pockets. In both cases, the evolution of the QPI vectors with energy and their behaviors in the nonmagnetic and magnetic impurity scattering cases can well be explained based on the evolution of the constant-energy contours and the sign structure of the SC order parameter. The QPI spectra presented in this paper can be compared with future scanning tunneling microscopy experiments to test whether there are SC phases in electron- and hole-doped Sr₂IrO₄ and what the pairing symmetry is.

No MeSH data available.


At n = 5.2, /ρ↑(q, ω)/ at fixed ω.The point at q = 0 is neglected in order to show weaker features at other wave vectors. (a–f) ω/Δ = −0.25, −0.5, −0.75, 0.25, 0.5, 0.75, for the nonmagnetic impurity scattering. (g–l) are the same as (a–f), but for the magnetic impurity scattering.
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f2: At n = 5.2, /ρ↑(q, ω)/ at fixed ω.The point at q = 0 is neglected in order to show weaker features at other wave vectors. (a–f) ω/Δ = −0.25, −0.5, −0.75, 0.25, 0.5, 0.75, for the nonmagnetic impurity scattering. (g–l) are the same as (a–f), but for the magnetic impurity scattering.

Mentions: In the presence of the impurity, we plot /ρ↑(q, ω)/ in Fig. 2 and several QPI wave vectors can be identified. For nonmagnetic impurity scattering [from Figs. 2(a) to 2(f)], three QPI wave vectors q1, q2 and q6 can be clearly seen evolving with energy. q1 is located along the (±1, ±1) directions and moves away from the origin as /ω/ increases. q2 and q6 are not located along the high-symmetry directions and they overlap after a 90 degree rotation. Furthermore, they are not so obvious at ω/Δ = 0.75 since they are masked by the high-intensity spots around them. In contrast, for magnetic impurity scattering [from Figs. 2(g) to 2(l)], q1, q2 and q6 become less clear and instead, another two vectors q3 and q7 can be identified evolving with energy. They are both located along the (0, ±1) and (±1, 0) directions and move towards the origin as /ω/ increases.


Possible superconductivity in Sr₂IrO₄ probed by quasiparticle interference.

Gao Y, Zhou T, Huang H, Wang QH - Sci Rep (2015)

At n = 5.2, /ρ↑(q, ω)/ at fixed ω.The point at q = 0 is neglected in order to show weaker features at other wave vectors. (a–f) ω/Δ = −0.25, −0.5, −0.75, 0.25, 0.5, 0.75, for the nonmagnetic impurity scattering. (g–l) are the same as (a–f), but for the magnetic impurity scattering.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4363866&req=5

f2: At n = 5.2, /ρ↑(q, ω)/ at fixed ω.The point at q = 0 is neglected in order to show weaker features at other wave vectors. (a–f) ω/Δ = −0.25, −0.5, −0.75, 0.25, 0.5, 0.75, for the nonmagnetic impurity scattering. (g–l) are the same as (a–f), but for the magnetic impurity scattering.
Mentions: In the presence of the impurity, we plot /ρ↑(q, ω)/ in Fig. 2 and several QPI wave vectors can be identified. For nonmagnetic impurity scattering [from Figs. 2(a) to 2(f)], three QPI wave vectors q1, q2 and q6 can be clearly seen evolving with energy. q1 is located along the (±1, ±1) directions and moves away from the origin as /ω/ increases. q2 and q6 are not located along the high-symmetry directions and they overlap after a 90 degree rotation. Furthermore, they are not so obvious at ω/Δ = 0.75 since they are masked by the high-intensity spots around them. In contrast, for magnetic impurity scattering [from Figs. 2(g) to 2(l)], q1, q2 and q6 become less clear and instead, another two vectors q3 and q7 can be identified evolving with energy. They are both located along the (0, ±1) and (±1, 0) directions and move towards the origin as /ω/ increases.

Bottom Line: Based on the possible superconducting (SC) pairing symmetries recently proposed, the quasiparticle interference (QPI) patterns in electron- and hole-doped Sr₂IrO₄ are theoretically investigated.In the electron-doped case, the QPI spectra can be explained based on a model similar to the octet model of the cuprates while in the hole-doped case, both the Fermi surface topology and the sign of the SC order parameter resemble those of the iron pnictides and there exists a QPI vector resulting from the interpocket scattering between the electron and hole pockets.In both cases, the evolution of the QPI vectors with energy and their behaviors in the nonmagnetic and magnetic impurity scattering cases can well be explained based on the evolution of the constant-energy contours and the sign structure of the SC order parameter.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing. 210023, China.

ABSTRACT
Based on the possible superconducting (SC) pairing symmetries recently proposed, the quasiparticle interference (QPI) patterns in electron- and hole-doped Sr₂IrO₄ are theoretically investigated. In the electron-doped case, the QPI spectra can be explained based on a model similar to the octet model of the cuprates while in the hole-doped case, both the Fermi surface topology and the sign of the SC order parameter resemble those of the iron pnictides and there exists a QPI vector resulting from the interpocket scattering between the electron and hole pockets. In both cases, the evolution of the QPI vectors with energy and their behaviors in the nonmagnetic and magnetic impurity scattering cases can well be explained based on the evolution of the constant-energy contours and the sign structure of the SC order parameter. The QPI spectra presented in this paper can be compared with future scanning tunneling microscopy experiments to test whether there are SC phases in electron- and hole-doped Sr₂IrO₄ and what the pairing symmetry is.

No MeSH data available.