scholarly journals Discovery of an ultra-quantum spin liquid

2021 ◽  
Author(s):  
Yanxing Yang ◽  
Cheng Tan ◽  
Zihao Zhu ◽  
J. Zhang ◽  
Zhaofeng Ding ◽  
...  
Keyword(s):  
Specific Heat ◽  
Quantum Fluctuations ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Singlet Ground State ◽  
Relaxation Rates ◽  
Scale Invariant ◽  
Liquid States ◽  
Increasing Temperature ◽  
Quantum Spin Liquid

Abstract Quantum fluctuations are expected to lead to highly entangled spin-liquid states in some two-dimensional spin-1/2 compounds. We have synthesized and measured thermodynamic properties and muon relaxation rates in two related such compounds, one of which is the least disordered of this kind synthesized hitherto and reveals intrinsic properties of a class of spin-liquids. Its measured properties can all be simply characterized by scale invariant time-dependent fluctuations with a single parameter. The specific heat divided by temperature and muon relaxation rates are both temperature independent at low temperatures, followed by a logarithmic decrease with increasing temperature. Even more remarkably, ∼57% of the magnetic entropy is missing down to temperatures of O(10−3) the exchange energy, independent of magnetic field up to gµBH > kBT . This is evidence that quantum fluctuations lead either to a gigantic specific heat peak from topological singlet excitations below such temperatures, or to an extensively degenerate topological singlet ground state. These results reveal an ultra-quantum state of matter.

scholarly journals Quantum-spin-liquid states in the two-dimensional kagome antiferromagnets ZnxCu4−x(OD)6Cl2

2007 ◽  
Vol 6 (11) ◽  
pp. 853-857 ◽  
Author(s):  
S.-H. Lee ◽  
H. Kikuchi ◽  
Y. Qiu ◽  
B. Lake ◽  
Q. Huang ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Spin Liquid ◽  
Two Dimensional ◽  
Liquid States ◽  
Quantum Spin Liquid

ROLE OF FRUSTRATION IN MAGNETISM AND THERMODYNAMIC PROPERTIES OF YMn2 AND β-Mn

1993 ◽  
Vol 07 (01n03) ◽  
pp. 1008-1012 ◽  
Author(s):  
M. SHIGA ◽  
K. YOSHIMOTO ◽  
H. NAKAMURA ◽  
H. WADA
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Ground State ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Spin Liquid

The temperature dependence of the magnetic susceptibility, the specific heat and the electrical resistivity of Y(Sc) (Mn1−xAlx)2 and β-Mn1−xAlx systems has been measured. It is shown that the ground state for x=0 is not a simple Pauli paramagnet but may be regarded as a quantum spin liquid. The substitution of Al for Mn results in the spin glass freezing. The role of frustration is discussed for understanding these phenomena.

scholarly journals Quantum spin-liquid states in an organic magnetic layer and molecular rotor hybrid

2020 ◽  
Vol 117 (47) ◽  
pp. 29555-29560
Author(s):  
Péter Szirmai ◽  
Cécile Mézière ◽  
Guillaume Bastien ◽  
Pawel Wzietek ◽  
Patrick Batail ◽  
...  
Keyword(s):  
Magnetic Measurements ◽  
Magnetic Layer ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Organic Crystals ◽  
Spin Liquids ◽  
Molecular Rotor ◽  
Low Dimensionality ◽  
Liquid States ◽  
Quantum Spin Liquid

The exotic properties of quantum spin liquids (QSLs) have continually been of interest since Anderson’s 1973 ground-breaking idea. Geometrical frustration, quantum fluctuations, and low dimensionality are the most often evoked material’s characteristics that favor the long-range fluctuating spin state without freezing into an ordered magnet or a spin glass at low temperatures. Among the few known QSL candidates, organic crystals have the advantage of having rich chemistry capable of finely tuning their microscopic parameters. Here, we demonstrate the emergence of a QSL state in [EDT-TTF-CONH2]2+[BABCO−] (EDT-BCO), where the EDT molecules with spin-1/2 on a triangular lattice form layers which are separated by a sublattice of BCO molecular rotors. By several magnetic measurements, we show that the subtle random potential of frozen BCO Brownian rotors suppresses magnetic order down to the lowest temperatures. Our study identifies the relevance of disorder in the stabilization of QSLs.

scholarly journals Kitaev exchange and field-induced quantum spin-liquid states in honeycomb α-RuCl3

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ravi Yadav ◽  
Nikolay A. Bogdanov ◽  
Vamshi M. Katukuri ◽  
Satoshi Nishimoto ◽  
Jeroen van den Brink ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Spin Liquid ◽  
Liquid States ◽  
Quantum Spin Liquid

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

2019 ◽  
Vol 116 (29) ◽  
pp. 14505-14510 ◽  
Author(s):  
Ruidan Zhong ◽  
Shu Guo ◽  
Guangyong Xu ◽  
Zhijun Xu ◽  
Robert J. Cava
Keyword(s):  
Triangular Lattice ◽  
Magnetic Ordering ◽  
Quantum Fluctuations ◽  
Quantum Spin ◽  
Low Energy ◽  
Spin Liquid ◽  
Effective Spin ◽  
Experimental Realization ◽  
Quantum Spin Liquid ◽  
Applied Fields

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 previously unreported compound, Na2BaCo(PO4)2, a geometrically frustrated system with effective spin-1/2 local moments for Co2+ ions on an isotropic 2-dimensional (2D) 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 0-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 material is an excellent candidate for the experimental realization of a QSL state.

scholarly journals Identification of magnetic interactions and high-field quantum spin liquid in α-RuCl3

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Han Li ◽  
Hao-Kai Zhang ◽  
Jiucai Wang ◽  
Han-Qing Wu ◽  
Yuan Gao ◽  
...  
Keyword(s):  
Specific Heat ◽  
High Field ◽  
Field Measurements ◽  
Spin Model ◽  
Quantum Spin ◽  
Magnetic Interactions ◽  
Spin Liquid ◽  
Plane Field ◽  
Out Of Plane ◽  
Quantum Spin Liquid

AbstractThe frustrated magnet α-RuCl3 constitutes a fascinating quantum material platform that harbors the intriguing Kitaev physics. However, a consensus on its intricate spin interactions and field-induced quantum phases has not been reached yet. Here we exploit multiple state-of-the-art many-body methods and determine the microscopic spin model that quantitatively explains major observations in α-RuCl3, including the zigzag order, double-peak specific heat, magnetic anisotropy, and the characteristic M-star dynamical spin structure, etc. According to our model simulations, the in-plane field drives the system into the polarized phase at about 7 T and a thermal fractionalization occurs at finite temperature, reconciling observations in different experiments. Under out-of-plane fields, the zigzag order is suppressed at 35 T, above which, and below a polarization field of 100 T level, there emerges a field-induced quantum spin liquid. The fractional entropy and algebraic low-temperature specific heat unveil the nature of a gapless spin liquid, which can be explored in high-field measurements on α-RuCl3.

scholarly journals Spin liquid and ferroelectricity close to a quantum critical point in PbCuTe2O6

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Christian Thurn ◽  
Paul Eibisch ◽  
Arif Ata ◽  
Maximilian Winkler ◽  
Peter Lunkenheimer ◽  
...  
Keyword(s):  
Quantum Critical Point ◽  
Quantum Fluctuations ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Spin Liquids ◽  
Range Magnetic Order ◽  
Powder Samples ◽  
Quantum Critical ◽  
Quantum Spin Liquid ◽  
Long Range Magnetic Order

AbstractGeometrical frustration among interacting spins combined with strong quantum fluctuations destabilize long-range magnetic order in favor of more exotic states such as spin liquids. By following this guiding principle, a number of spin liquid candidate systems were identified in quasi-two-dimensional (quasi-2D) systems. For 3D, however, the situation is less favorable as quantum fluctuations are reduced and competing states become more relevant. Here we report a comprehensive study of thermodynamic, magnetic and dielectric properties on single crystalline and pressed-powder samples of PbCuTe2O6, a candidate material for a 3D frustrated quantum spin liquid featuring a hyperkagome lattice. Whereas the low-temperature properties of the powder samples are consistent with the recently proposed quantum spin liquid state, an even more exotic behavior is revealed for the single crystals. These crystals show ferroelectric order at TFE ≈ 1 K, accompanied by strong lattice distortions, and a modified magnetic response—still consistent with a quantum spin liquid—but with clear indications for quantum critical behavior.

scholarly journals Quantum spin liquid states

2017 ◽  
Vol 89 (2) ◽  
Author(s):  
Yi Zhou ◽  
Kazushi Kanoda ◽  
Tai-Kai Ng
Keyword(s):  
Quantum Spin ◽  
Spin Liquid ◽  
Liquid States ◽  
Quantum Spin Liquid
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