Polarization-resolved Raman spectroscopy of α−RuCl3 and evidence of room-temperature two-dimensional magnetic scattering
| Autor: | J. R. Simpson, P. Lampen-Kelley, S. E. Nagler, Amber McCreary, A. R. Hight Walker, Jiaqiang Yan, D. G. Mandrus, Thuc Mai, Nicholas P. Butch, R. Valdés Aguilar |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Photon Condensed matter physics Phonon Scattering Exchange interaction 02 engineering and technology 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences symbols.namesake 0103 physical sciences symbols Quantum spin liquid 010306 general physics 0210 nano-technology Raman spectroscopy Single crystal |
| Zdroj: | Physical Review B. 100 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.100.134419 |
| Popis: | Polarization-resolved Raman spectroscopy was performed and analyzed from large, high-quality, monodomain single crystal of $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{RuCl}}_{3}$, a proximate Kitaev quantum spin liquid. Spectra were collected with laser polarizations parallel and perpendicular to the honeycomb plane. Pairs of nearly degenerate phonons were discovered and show either a fourfold or twofold polarization angle dependence in their Raman intensity, thereby providing evidence to definitively assign the bulk crystal point group as ${C}_{2h}$. The low-frequency continuum that is often attributed to scattering from pairs of Majorana fermions was also examined and found to disappear when the laser excitation and scattered photon polarizations were perpendicular to the honeycomb plane. This disappearance, along with the behavior of the phonon spectrum in the same polarization configuration, strongly suggests that the scattering continuum is two-dimensional. We argue that this scattering continuum originates from the Kitaev magnetic interactions that survives up to room temperature, a scale larger than the bare Kitaev exchange energy of approximately 50 K. |
| Databáze: | OpenAIRE |
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