Abstract
Motivated by novel 5d-electron systems such as Sr2IrO4 and Ba2IrO4, we study the ground state of a three-orbital Hubbard model with a spin-orbit coupling by using a variational Monte Carlo method. The obtained ground-state phase diagram reveals that an antiferromagnetic state, stable at around the electron density n = 5, is destabilized by carrier doping and that the ground state becomes superconducting. Similar to high-T c cuprates, a large asymmetry of the phase diagram between electron doping (n > 5) and hole doping (n < 5) is also found, which can be understood as the band structure effect. Due to the large spin-orbit coupling which entangles spin and orbital degrees of freedom, the pseudospin becomes a good quantum number, and the superconductivity found here is characterized by the \(d_{x^2 - y^2 }\)-wave “pseudospin singlet” pairing.
Similar content being viewed by others
References
J. J. Randall Jr, L. Katz and R. Ward, J. Am. Chem. Soc. 79, 266 (1957).
H. Okabe, M. Isobe, E. Takayama-Muromachi, A. Koda, S. Takeshita, M. Hiraishi, M. Miyazaki, R. Kadono, Y. Miyake and J. Akimitsu, Phys. Rev. B 83, 155118 (2011).
B. J. Kim, Hosub Jin, S. J. Moon, J.-Y. Kim, B.-G. Park, C. S. Leem, J. Yu, T. W. Noh, C. Kim, S.-J. Oh, J.-H. Park, V. Durairaj, G. Cao and E. Rotenberg, Phys. Rev. Lett. 101, 076402 (2008).
B. J. Kim, H. Ohsumi, T. Komesu, S. Sakai, T. Morita, H. Takagi and T. Arima, Science 323, 1329 (2009).
G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 102, 017205 (2009).
H. Watanabe, T. Shirakawa and S. Yunoki, Phys. Rev. Lett. 105, 216410 (2010).
J. Kim, D. Casa, M. H. Upton, T. Gog, Y.-J. Kim, J. F. Mitchell, M. van Veenendaal, M. Daghofer, J. van den Brink, G. Khaliullin and B. J. Kim, Phys. Rev. Lett. 108, 177003 (2012).
S. Fujiyama, H. Ohsumi, T. Komesu, J. Matsuno, B. J. Kim, M. Takata, T. Arima and H. Takagi, Phys. Rev. Lett. 108, 247212 (2012).
F. Wang and T. Senthil, Phys. Rev. Lett. 106, 136402 (2011).
H. Watanabe, T. Shirakawa and S. Yunoki, Phys. Rev. Lett. 110, 027002 (2013).
S. Sorella, Phys. Rev. B 64, 024512 (2001).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Watanabe, H., Shirakawa, T. & Yunoki, S. A novel superconductivity in Ir oxides with a large spin-orbit coupling. Journal of the Korean Physical Society 62, 1848–1851 (2013). https://doi.org/10.3938/jkps.62.1848
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.3938/jkps.62.1848