A Novel Superconductivity in Ir Oxides with a Large Spin-orbit Coupling

다국어 초록 (Multilingual Abstract)

Motivated by novel 5d-electron systems such as Sr2IrO4 and Ba2IrO4, we study the ground stateof a three-orbital Hubbard model with a spin-orbit coupling by using a variational Monte Carlomethod. The obtained ground-state phase diagram reveals that an antiferromagnetic state, stableat around the electron density n = 5, is destabilized by carrier doping and that the ground statebecomes superconducting. Similar to high-Tc cuprates, a large asymmetry of the phase diagrambetween electron doping (n > 5) and hole doping (n < 5) is also found, which can be understoodas the band structure effect. Due to the large spin-orbit coupling which entangles spin and orbitaldegrees of freedom, the pseudospin becomes a good quantum number, and the superconductivityfound here is characterized by the dx2−y2-wave “pseudospin singlet” pairing.

참고문헌 (Reference)

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