Exchange interactions in d5 Kitaev materials: From Na2IrO3 to α−RuCl3

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F22%3A00129107" target="_blank" >RIV/00216224:14310/22:00129107 - isvavai.cz</a>

Result on the web

<a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.214411" target="_blank" >https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.214411</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.105.214411" target="_blank" >10.1103/PhysRevB.105.214411</a>

Result language

angličtina

Original language name

Exchange interactions in d5 Kitaev materials: From Na2IrO3 to α−RuCl3

Original language description

We present an analytical study of the exchange interactions between pseudospin one-half d5 ions in honeycomb lattices with edge-shared octahedra. Various exchange channels involving Hubbard U, charge-transfer excitations, and cyclic exchange are considered. Hoppings within t2g orbitals as well as between t2g and eg orbitals are included. Special attention is paid to the trigonal crystal field Δ effects on the exchange parameters. The obtained exchange Hamiltonian is dominated by ferromagnetic Kitaev interaction K within a wide range of Δ. It is found that a parameter region close to the charge-transfer insulator regime and with a small Δ is most promising to realize the Kitaev spin liquid phase. Two representative honeycomb materials Na2IrO3 and α-RuCl3 are discussed based on our theory. We have found that both materials share dominant ferromagnetic K and positive nondiagonal Γ values. However, their Heisenberg J terms have opposite signs: AFM J&gt;0 in Na2IrO3 and FM J&lt;0 in α-RuCl3. This brings different magnetic fluctuations and results in their different magnetization behaviors and spin excitation spectra. Proximity to FM state due to the large FM J is emphasized in α-RuCl3. The differences between the exchange couplings of these two materials originate from the opposite Δ values, indicating that the crystal field can serve as an efficient control parameter to tune the magnetic properties of d5 spin-orbit Mott insulators.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/GA19-16937S" target="_blank" >GA19-16937S: Frustrated and non-frustrated soft-spin systems in relativistic Mott insulators</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Volume of the periodical

105

Issue of the periodical within the volume

21

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

1-12

UT code for WoS article

000821648400002

EID of the result in the Scopus database

2-s2.0-85131855325