Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice

Abstract

Currently under active study in condensed matter physics, both theoretically and experimentally, are quantum spin liquid (QSL) states, in which no long-range magnetic ordering appears at low temperatures due to strong quantum fluctuations of the magnetic moments. The existing QSL candidates all have their intrinsic disadvantages, however, and solid evidence for quantum fluctuations is scarce. Here we report a new compound, Na${}_2$BaCo(PO${}_4$)${}_2$, a geometrically frustrated system with effective spin-1/2 local moments for Co${}^{2+}$ ions on an isotropic two-dimensional triangular lattice. Magnetic susceptibility and neutron scattering experiments show no magnetic ordering down to 0.05 K. Thermodynamic measurements show that there is a tremendous amount of magnetic entropy present below 1 K in zero applied magnetic field. The presence of localized low-energy spin fluctuations is revealed by inelastic neutron measurements. At low applied fields, these spin excitations are confined to low energy and contribute to the anomalously large specific heat. In larger applied fields, the system reverts to normal behavior as evident by both neutron and thermodynamic results. Our experimental characterization thus reveals that this new material is an excellent candidate for the experimental realization of a quantum spin liquid state.

References in corpus (14)

• Fractionalized excitations in the spin liquid state of a kagomé lattice antiferromagnet
• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4
• Experimental realization of a 2D fractional quantum spin liquid
• Rare-earth triangular lattice spin liquid: a single-crystal study of YbMgGaO${}_4$
• Evidence for a spinon Fermi surface in a triangular lattice quantum spin liquid candidate
• Gapless quantum spin liquid ground state in the two-dimensional spin-1/2 triangular antiferromagnet YbMgGaO${}_4$
• Experimental Realization of Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet
• Disorder-Induced Mimicry of a Spin Liquid in YbMgGaO${}_4$
• Spin-glass ground state in a triangular-lattice compound YbZnGaO${}_4$
• Refining the Spin Hamiltonian in the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu${}_3$(OH)${}_6$Cl${}_2$ using Single Crystals
• Absolute cross-section normalization of magnetic neutron scattering data
• Fractionalized excitations in the partially magnetized spin liquid candidate YbMgGaO4
• Detecting spin fractionalization in a spinon Fermi surface spin liquid

Cited by in corpus (55)

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• Spin liquid state in a rare-earth hyperkagome lattice
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• Phase Diagram of the Easy-Axis Triangular-Lattice $J_1-J_2$ Model
• Continuum of spin excitations in an ordered magnet
• Rare-Earth Chalcogenides: An Inspiring Playground For Exploring Frustrated Magnetism
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• Spin liquid behavior of a three-dimensional magnetic system Ba${}_3$NiIr${}_2$O${}_9$ with $S$ = 1
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• NMR study of supersolid phases in the triangular-lattice antiferromagnet Na2BaCo(PO4)2
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• Spin Seebeck Effect of Triangular-lattice Spin Supersolid
• Pseudo-Majorana functional renormalization for frustrated XXZ spin-1/2 models with field or magnetization along the spin-Z direction at finite temperature
• Noncentrosymmetric Triangular Magnet CaMnTeO${}_6$: Strong Quantum Fluctuations and Role of s0 vs. s2 Electronic States in Competing Exchange Interactions
• Spin structures and phase diagrams of the spin-$\frac{5}{2}$ triangular-lattice antiferromagnet Na${}_2$BaMn(PO${}_4$)${}_2$ under magnetic field
• Field tunable BKT and quantum phase transitions in spin-1/2 triangular lattice antiferromagnet
• Doping-induced structural transformation in the spin-1/2 triangular-lattice antiferromagnet Na${}_2$Ba${}_{1-x}$Sr${}_x$Co(PO${}_4$)${}_2$
• Signatures of a gapless quantum spin liquid in the Kitaev material Na${}_3$Co${}_{2-x}$Zn${}_x$SbO${}_6$
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• Magnetically disordered ground state in the triangular-lattice antiferromagnets Rb${}_3$Yb(VO${}_4$)${}_2$ and Cs${}_3$Yb(VO${}_4$)${}_2$
• A primer on Kitaev Model: Basic aspects, material realization, and recent experiments
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