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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

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

Projekt

<a href="/cs/project/GA19-16937S" target="_blank" >GA19-16937S: Frustrované a nefrustrované spinové systémy s měkkými spiny v relativistických Mottových izolantech</a><br>

Návaznosti

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

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Svazek periodika

105

Číslo periodika v rámci svazku

21

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

1-12

Kód UT WoS článku

000821648400002

EID výsledku v databázi Scopus

2-s2.0-85131855325