Evidence for Magnetic Fractional Excitations in a Kitaev Quantum-Spin-Liquid Candidate alpha-RuCl3

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10439369" target="_blank" >RIV/00216208:11320/22:10439369 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=L9dH597-ec" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=L9dH597-ec</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/0256-307X/39/2/027501" target="_blank" >10.1088/0256-307X/39/2/027501</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Evidence for Magnetic Fractional Excitations in a Kitaev Quantum-Spin-Liquid Candidate alpha-RuCl3

Popis výsledku v původním jazyce

It is known that alpha-RuCl3 has been studied extensively because of its proximity to the Kitaev quantum-spin-liquid (QSL) phase and the possibility of approaching it by tuning the competing interactions. Here we present the first polarized inelastic neutron scattering study on alpha-RuCl3 single crystals to explore the scattering continuum around the Gamma point at the Brillouin zone center, which was hypothesized to be resulting from the Kitaev QSL state but without concrete evidence. With polarization analyses, we find that, while the spin-wave excitations around the M point vanish above the transition temperature T (N), the pure magnetic continuous excitations around the Gamma point are robust against temperature. Furthermore, by calculating the dynamical spin-spin correlation function using the cluster perturbation theory, we derive magnetic dispersion spectra based on the K-Gamma model, which involves with a ferromagnetic Kitaev interaction of -7.2 meV and an off-diagonal interaction of 5.6 meV. We find this model can reproduce not only the spin-wave excitation spectra around the M point, but also the non-spin-wave continuous magnetic excitations around the Gamma point. These results provide evidence for the existence of fractional excitations around the Gamma point originating from the Kitaev QSL state, and further support the validity of the K-Gamma model as the effective minimal spin model to describe alpha-RuCl3.

Název v anglickém jazyce

Evidence for Magnetic Fractional Excitations in a Kitaev Quantum-Spin-Liquid Candidate alpha-RuCl3

Popis výsledku anglicky

It is known that alpha-RuCl3 has been studied extensively because of its proximity to the Kitaev quantum-spin-liquid (QSL) phase and the possibility of approaching it by tuning the competing interactions. Here we present the first polarized inelastic neutron scattering study on alpha-RuCl3 single crystals to explore the scattering continuum around the Gamma point at the Brillouin zone center, which was hypothesized to be resulting from the Kitaev QSL state but without concrete evidence. With polarization analyses, we find that, while the spin-wave excitations around the M point vanish above the transition temperature T (N), the pure magnetic continuous excitations around the Gamma point are robust against temperature. Furthermore, by calculating the dynamical spin-spin correlation function using the cluster perturbation theory, we derive magnetic dispersion spectra based on the K-Gamma model, which involves with a ferromagnetic Kitaev interaction of -7.2 meV and an off-diagonal interaction of 5.6 meV. We find this model can reproduce not only the spin-wave excitation spectra around the M point, but also the non-spin-wave continuous magnetic excitations around the Gamma point. These results provide evidence for the existence of fractional excitations around the Gamma point originating from the Kitaev QSL state, and further support the validity of the K-Gamma model as the effective minimal spin model to describe alpha-RuCl3.

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

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Chinese Physics Letters

ISSN

0256-307X

e-ISSN

1741-3540

Svazek periodika

39

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

027501

Kód UT WoS článku

000752027200001

EID výsledku v databázi Scopus

2-s2.0-85125754438