Possible superconductivity in Sr₂IrO₄ probed by quasiparticle interference.

Yi Gao,Huaixiang Huang,Tao Zhou,Qiang-Hua Wang

doi:10.1038/srep09251

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.

Highlights

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 order to search for an experimental test of the above two theories, we propose to measure the quasiparticle interference (QPI) patterns in both electron- and hole-doped Sr2IrO4 by scanning tunneling microscopy (STM)

Summary

Correspondence and requests for materials should be addressed to

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. 15 and 16 theoretically investigated the superconducting (SC) properties in both electron- and hole-doped Sr2IrO4 They found that, in the electron-doped case, a SC phase exists and the pairing contains both intraorbital and interorbital components as well as both singlet and triplet components of t2g electrons, while the pairing symmetry on the Fermi surface is dx2{y2 -wave (or dxÃ2{y2 -wave as denoted by Ref. 16) and the pairing function respects time-reversal symmetry (TRS), similar to the cuprates. By measuring the QPI patterns, we can determine whether the SC phase exists in the electron- and hole-doped cases, and the SC pairing symmetry

Mk yk

Results and discussion

Mott insulator

Heisenberg behavior of

Additional information