scholarly journals Possible itinerant excitations and quantum spin state transitions in the effective spin-1/2 triangular-lattice antiferromagnet Na2BaCo(PO4)2

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Li ◽  
Q. Huang ◽  
X. Y. Yue ◽  
W. J. Chu ◽  
Q. Chen ◽  
...  
Keyword(s):  
Spin State ◽  
Triangular Lattice ◽  
Quantum Spin ◽  
State Transitions ◽  
Effective Spin ◽  
Triangular Lattice Antiferromagnet

scholarly journals Quantum spin state transitions in the spin-1 equilateral triangular lattice antiferromagnet Na2BaNi(PO4)2

2021 ◽  
Vol 104 (10) ◽  
Author(s):  
N. Li ◽  
Q. Huang ◽  
A. Brassington ◽  
X. Y. Yue ◽  
W. J. Chu ◽  
...  
Keyword(s):  
Spin State ◽  
Triangular Lattice ◽  
Quantum Spin ◽  
State Transitions ◽  
Triangular Lattice Antiferromagnet

scholarly journals Survival of itinerant excitations and quantum spin state transitions in YbMgGaO4 with chemical disorder

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
X. Rao ◽  
G. Hussain ◽  
Q. Huang ◽  
W. J. Chu ◽  
N. Li ◽  
...  
Keyword(s):  
Spin State ◽  
Magnetic Ordering ◽  
Temperature Limit ◽  
Quantum Spin ◽  
Spin Fluctuations ◽  
State Transitions ◽  
Spin Liquid ◽  
Magnetic Ground State ◽  
Effective Spin ◽  
Ideal System

AbstractA 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. YbMgGaO4, a triangular lattice antiferromagnet with effective spin-1/2 Yb3+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 YbMgGaO4 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 κ0/T term and series of quantum spin state transitions in the zero temperature limit for YbMgGaO4. These observations strongly suggest that a QSL state with itinerant excitations and quantum spin fluctuations survives disorder in YbMgGaO4.

scholarly journals Pressure-tuning the quantum spin Hamiltonian of the triangular lattice antiferromagnet Cs2CuCl4

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
S. A. Zvyagin ◽  
D. Graf ◽  
T. Sakurai ◽  
S. Kimura ◽  
H. Nojiri ◽  
...  
Keyword(s):  
Triangular Lattice ◽  
Quantum Spin ◽  
Spin Hamiltonian ◽  
Pressure Tuning ◽  
Triangular Lattice Antiferromagnet

scholarly journals Instability of a quantum spin liquid in an organic triangular-lattice antiferromagnet

2010 ◽  
Vol 6 (9) ◽  
pp. 673-676 ◽  
Author(s):  
T. Itou ◽  
A. Oyamada ◽  
S. Maegawa ◽  
R. Kato
Keyword(s):  
Triangular Lattice ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Spin Liquid ◽  
Triangular Lattice Antiferromagnet

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 Spinon Fermi surface spin liquid in a triangular lattice antiferromagnet NaYbSe2

2020 ◽  
Author(s):  
Peng-Ling Dai ◽  
Gaoning Zhang ◽  
Yaofeng Xie ◽  
Chunruo Duan ◽  
Yonghao Gao ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Neutron Scattering ◽  
Triangular Lattice ◽  
Inelastic Neutron Scattering ◽  
Quantum Spin ◽  
Spin Excitation ◽  
Magnetic Excitation ◽  
Excitation Spectra ◽  
Effective Spin ◽  
Scattering Measurements

Abstract Triangular lattice of rare-earth ions with interacting effective spin-1/2 local moments is an ideal platform to explore the physics of quantum spin liquids (QSLs) in the presence of strong spin-orbit coupling, crystal electric fields, and geometrical frustration. The Yb delafossites, NaYbCh2 (Ch=O, S, Se) with Yb ions forming a perfect triangular lattice, have been suggested to be candidates for QSLs. Previous thermodynamics, nuclear magnetic resonance, and powder sample neutron scattering measurements on NaYbCh2 have supported the suggestion of the QSL ground states. The key signature of a QSL, the spin excitation continuum, arising from the spin quantum number fractionalization, has not been observed. Here we perform both elastic and inelastic neutron scattering measurements as well as detailed thermodynamic measurements on high-quality single crystalline NaYbSe2 samples to confirm the absence of long-range magnetic order down to 40 mK, and further reveal a clear signature of magnetic excitation continuum extending from 0.1 to 2.5 meV. By comparing the structure of our magnetic excitation spectra with the theoretical expectation from the spinon continuum, we conclude that the ground state of NaYbSe2 is a QSL with a spinon Fermi surface.

Sign in / Sign up

Export Citation Format

Share Document