## This content will become publicly available on August 6, 2020

## Deriving models for the Kitaev spin-liquid candidate material $\alpha \text{-}{\mathrm{RuCl}}_{3}$ from first principles

## Abstract

We use the constrained random phase approximation to derive from first principles the Ru-$$t_{2_g}$$ Wannier-function-based model for the Kitaev spin-liquid candidate material $α$-RuCl _{3}. We find the nonlocal Coulomb repulsion to be sizable compared to the local one. In addition we obtain the contribution to the Hamiltonian from the spin-orbit coupling and find it to also contain non-negligible nonlocal terms. We invoke strong-coupling perturbation theory to investigate the influence of these nonlocal elements of the Coulomb repulsion and the spin-orbit coupling on the magnetic interactions. We find that the nonlocal Coulomb repulsions cause a strong enhancement of the magnetic interactions, which deviate from experimental fits reported in the literature. Our results contribute to the understanding and design of quantum spin-liquid materials via first-principles calculations.

- Authors:

- Univ. of Tennessee, Knoxville, TN (United States)
- Louisiana State Univ., Baton Rouge, LA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

- Publication Date:

- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1566977

- Alternate Identifier(s):
- OSTI ID: 1547988

- Grant/Contract Number:
- AC05-00OR22725

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Physical Review B

- Additional Journal Information:
- Journal Volume: 100; Journal Issue: 7; Journal ID: ISSN 2469-9950

- Publisher:
- American Physical Society (APS)

- Country of Publication:
- United States

- Language:
- English

### Citation Formats

```
Eichstaedt, Casey, Zhang, Yi, Laurell, Pontus Bengt Johan, Okamoto, Satoshi, Eguiluz, Adolfo, and Berlijn, Tom. Deriving models for the Kitaev spin-liquid candidate material α-RuCl3 from first principles. United States: N. p., 2019.
Web. doi:10.1103/PhysRevB.100.075110.
```

```
Eichstaedt, Casey, Zhang, Yi, Laurell, Pontus Bengt Johan, Okamoto, Satoshi, Eguiluz, Adolfo, & Berlijn, Tom. Deriving models for the Kitaev spin-liquid candidate material α-RuCl3 from first principles. United States. doi:10.1103/PhysRevB.100.075110.
```

```
Eichstaedt, Casey, Zhang, Yi, Laurell, Pontus Bengt Johan, Okamoto, Satoshi, Eguiluz, Adolfo, and Berlijn, Tom. Tue .
"Deriving models for the Kitaev spin-liquid candidate material α-RuCl3 from first principles". United States. doi:10.1103/PhysRevB.100.075110.
```

```
@article{osti_1566977,
```

title = {Deriving models for the Kitaev spin-liquid candidate material α-RuCl3 from first principles},

author = {Eichstaedt, Casey and Zhang, Yi and Laurell, Pontus Bengt Johan and Okamoto, Satoshi and Eguiluz, Adolfo and Berlijn, Tom},

abstractNote = {We use the constrained random phase approximation to derive from first principles the Ru-$t_{2_g}$ Wannier-function-based model for the Kitaev spin-liquid candidate material $α$-RuCl3. We find the nonlocal Coulomb repulsion to be sizable compared to the local one. In addition we obtain the contribution to the Hamiltonian from the spin-orbit coupling and find it to also contain non-negligible nonlocal terms. We invoke strong-coupling perturbation theory to investigate the influence of these nonlocal elements of the Coulomb repulsion and the spin-orbit coupling on the magnetic interactions. We find that the nonlocal Coulomb repulsions cause a strong enhancement of the magnetic interactions, which deviate from experimental fits reported in the literature. Our results contribute to the understanding and design of quantum spin-liquid materials via first-principles calculations.},

doi = {10.1103/PhysRevB.100.075110},

journal = {Physical Review B},

number = 7,

volume = 100,

place = {United States},

year = {2019},

month = {8}

}

Works referenced in this record:

##
Generalized Gradient Approximation Made Simple

journal, October 1996

- Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
- Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868