Year: 2020
Type: article
Abstract: The rare-earth magnet TmMgGaO 4 is proposed to be an intrinsic quantum Ising magnet described by the antiferromagnetic transverse field Ising model (TFIM) on a triangular lattice, where the relevant degrees of freedom are the nondegenerate dipole-multipole doublets of the Tm 3+ ions and the transverse field has an intrinsic origin from the weak splitting of the doublet.We compare this special doublet of Tm 3+ with the dipole-octupole Kramers doublet.We study the proposed effective model for the Tm-based triangular lattice and consider the effects of external magnetic fields and finite temperatures.From the orthogonal operator approach, we show that the TFIM with the three-sublattice intertwined ordered state agrees with the experiments and further clarify the discrepancy in the numbers of the magnetic sublattices and the measured magnon branches.We make specific predictions for the evolution of the magnetic properties with the external magnetic field.Furthermore, we demonstrate that an emergent U(1) symmetry emerges in thermal melting of the underlying orders and at the criticality, and summarize the previously known signatures related to the finite-temperature Berezinskii-Kosterlitz-Thouless physics.We discuss the broad relevance of intrinsic quantum Ising magnets to many other systems, especially Tm-based materials.
Source: Physical Review Research
Authors: Changle Liu, Chun-Jiong Huang, Gang Chen
Language: Latvian
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,625
OpenAlex ID: W2995257074