### Abstract

Motivated by recent experiments on Sr_{2}IrO_{4}, we study the ground state properties of a two-dimensional three-band Hubbard model with a strong relativistic spin-orbit coupling. Using the exact diagonalization technique, the dynamical magnetic structure factor M(q, ω) is calculated to examine the low-energy magnetic excitations. We find that the low-energy excitations in M(q, ω) are well described by an effective Heisenberg model composed of a local Kramers doublet of an effective total angular momentum J_{eff} | - | = 1/2. The antiferromagnetic exchange interaction estimated from M(q, ω) is as large as ∼ 80 meV, which is in good quantitative agreement with experiments. To study a possible long-range ordered state in the thermodynamic limit, we use the variational cluster approximation based on the self-energy functional theory, which is parallelized to accelerate the calculations. We find the ground state where the local Kramers doublet is in-plane antiferromagnetic ally ordered.

Original language | English |
---|---|

Article number | 012068 |

Journal | Journal of Physics: Conference Series |

Volume | 454 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2013 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

_{2}IrO

_{4}

*Journal of Physics: Conference Series*,

*454*(1), [012068]. https://doi.org/10.1088/1742-6596/454/1/012068

**Theoretical studies of a three-band Hubbard model with a strong spin-orbit coupling for 5d transition metal oxide Sr _{2}IrO_{4} .** / Shirakawa, Tomonori; Watanabe, Hiroshi; Yunoki, Seiji.

Research output: Contribution to journal › Article

_{2}IrO

_{4}',

*Journal of Physics: Conference Series*, vol. 454, no. 1, 012068. https://doi.org/10.1088/1742-6596/454/1/012068

_{2}IrO

_{4}Journal of Physics: Conference Series. 2013;454(1). 012068. https://doi.org/10.1088/1742-6596/454/1/012068

}

TY - JOUR

T1 - Theoretical studies of a three-band Hubbard model with a strong spin-orbit coupling for 5d transition metal oxide Sr2IrO4

AU - Shirakawa, Tomonori

AU - Watanabe, Hiroshi

AU - Yunoki, Seiji

PY - 2013

Y1 - 2013

N2 - Motivated by recent experiments on Sr2IrO4, we study the ground state properties of a two-dimensional three-band Hubbard model with a strong relativistic spin-orbit coupling. Using the exact diagonalization technique, the dynamical magnetic structure factor M(q, ω) is calculated to examine the low-energy magnetic excitations. We find that the low-energy excitations in M(q, ω) are well described by an effective Heisenberg model composed of a local Kramers doublet of an effective total angular momentum Jeff | - | = 1/2. The antiferromagnetic exchange interaction estimated from M(q, ω) is as large as ∼ 80 meV, which is in good quantitative agreement with experiments. To study a possible long-range ordered state in the thermodynamic limit, we use the variational cluster approximation based on the self-energy functional theory, which is parallelized to accelerate the calculations. We find the ground state where the local Kramers doublet is in-plane antiferromagnetic ally ordered.

AB - Motivated by recent experiments on Sr2IrO4, we study the ground state properties of a two-dimensional three-band Hubbard model with a strong relativistic spin-orbit coupling. Using the exact diagonalization technique, the dynamical magnetic structure factor M(q, ω) is calculated to examine the low-energy magnetic excitations. We find that the low-energy excitations in M(q, ω) are well described by an effective Heisenberg model composed of a local Kramers doublet of an effective total angular momentum Jeff | - | = 1/2. The antiferromagnetic exchange interaction estimated from M(q, ω) is as large as ∼ 80 meV, which is in good quantitative agreement with experiments. To study a possible long-range ordered state in the thermodynamic limit, we use the variational cluster approximation based on the self-energy functional theory, which is parallelized to accelerate the calculations. We find the ground state where the local Kramers doublet is in-plane antiferromagnetic ally ordered.

UR - http://www.scopus.com/inward/record.url?scp=84885626735&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84885626735&partnerID=8YFLogxK

U2 - 10.1088/1742-6596/454/1/012068

DO - 10.1088/1742-6596/454/1/012068

M3 - Article

VL - 454

JO - Journal of Physics: Conference Series

JF - Journal of Physics: Conference Series

SN - 1742-6588

IS - 1

M1 - 012068

ER -