Survival of itinerant excitations and quantum spin state transitions in YbMgGaO${}_4$ with chemical disorder

Abstract

A recent focus of quantum spin liquid (QSL) studies is how disorder/randomness in a QSL candidate affects its true magnetic ground state. The ultimate question is whether the QSL survives disorder or the disorder leads to a "spin-liquid-like" state, such as the proposed random-singlet (RS) state. Since disorder is a standard feature of most QSL candidates, this question represents a major challenge for QSL candidates. YbMgGaO${}_4$, a triangular lattice antiferromagnet with effective spin-1/2 Yb${}^{3+}$ ions, is an ideal system to address this question, since it shows no long-range magnetic ordering with Mg/Ga site disorder. Despite the intensive study, it remains unresolved as to whether YbMgGaO${}_4$ is a QSL or in the RS state. Here, through ultralow-temperature thermal conductivity and magnetic torque measurements, plus specific heat and DC magnetization data, we observed a residual ${\kappa }_0/T$ term and series of quantum spin state transitions in the zero temperature limit for YbMgGaO${}_4$. These observations strongly suggest that a QSL state with itinerant excitations and quantum spin fluctuations survives disorder in YbMgGaO${}_4$.

31 pages, 10 figures

References in corpus (18)

• Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4
• Unusual ordered phases of highly frustrated magnets: a review
• $\mu$SR evidence for the U(1) quantum spin liquid ground state in the triangular antiferromagnet YbMgGaO${}_4$
• Crystalline Electric Field Randomness in the Triangular Lattice Spin-Liquid YbMgGaO${}_4$
• Anisotropic field-induced ordering in the triangular-lattice quantum spin liquid NaYbSe${}_2$
• Physical realization of a quantum spin liquid based on a novel frustration mechanism
• Possible valence-bond condensation in the frustrated cluster magnet LiZn2Mo3O8
• Absence of magnetic thermal conductivity in the quantum spin liquid candidate YbMgGaO4
• Quantum Oscillations of Electrical Resistivity in an Insulator
• Quantum stabilization of 1/3-magnetization plateau in Cs_2CuBr_4
• Field-induced magnetic transition and spin fluctuation in quantum spin liquid candidate CsYbSe${}_2$
• The phase diagram of the antiferromagnetic XXZ model on the triangular lattice
• Microscopic Model Calculations for the Magnetization Process of Layered Triangular-Lattice Quantum Antiferromagnets
• Transport Properties of a spinon Fermi surface coupled to a U(1) gauge field
• Rearrangement of uncorrelated valence bonds evidenced by low-energy spin excitations in YbMgGaO4
• Heat transport study of the spin liquid candidate 1T-TaS2
• Order by quenched disorder in the model triangular antiferromagnet RbFe(MoO4)2
• Half-magnetization plateau in a Heisenberg antiferromagnet on a triangular lattice

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