2022 CAP Congress / Congrès de l'ACP 2022

(G*) Dynamic and frozen quantum magnetism in the ground states of triangular lattice magnets YbMgGaO4, ErMgGaO4 and YbCoGaO4 from inelastic neutron scattering

8 Jun 2022, 11:00

15m

MDCL 1010 (McMaster University)

Oral Competition (Graduate Student) / Compétition orale (Étudiant(e) du 2e ou 3e cycle) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) W1-9 Quantum Magnetism (DCMMP) | Magnétisme quantique (DPMCM)

Speaker

Ms Symphony (Hsiao-Yuan) Huang (McMaster University)

Description

The putative quantum spin liquid (QSL) state exhibited by YbMgGaO${}_4$ is largely
ascribed to the quasi-2D triangular lattice which the magnetic Yb${}^{3+}$ moments
decorate in concert with anisotropic exchange and disorder in neighbouring
disordered Mg${}^{2+}$/Ga${}^{3+}$ bilayers [1,2,3]. We present new inelastic neutron
scattering (INS) measurements on YbMgGaO${}_4$ as well as its isostructural sister
compounds: ErMgGaO${}_4$ and YbCoGaO${}_4$. Each material was synthesized as a
phase-pure powder and INS measurements were performed on IN6-Sharp with E${}_i$
= 3.1 meV at the Institut Laue-Langevin. We discuss the observed hallmarks of a
QSL in YbMgGaO${}_4$ and contrast these with signatures of frozen spin correlations
in each of ErMgGaO${}_4$ and YbCoGaO${}_4$ in the INS measurements. The case of
YbCoGaO${}_4$ is an interesting one as it displays the interplay between a QSL-like
state associated with the Yb${}^{3+}$ magnetism, interleaved with a two-dimensional
spin glass state originating from the disordered Co${}^{2+}$ magnetism.

[1] Paddison, J., Daum, M., Mourigal, M. et al. Nature Phys 13, 117–122 (2017)
[2] Li, Y., Adroja, D., Zhang, Q. et al. Phys. Rev. Lett. 118, 107202 (2017)
[3] Zhu, Z., Maksimov, P. A., Chernyshev, A. L. et al. Phys. Rev. Lett. 119,
157201 (2017)