The Experts below are selected from a list of 3045 Experts worldwide ranked by ideXlab platform
Andreas P. Schnyder - One of the best experts on this subject based on the ideXlab platform.
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Z 2 topological quantum Paramagnet on a honeycomb bilayer
Physical Review B, 2019Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a time-reversal-symmetry protected ${\mathbb{Z}}_{2}$ topological quantum Paramagnet (topological triplon insulator) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial ${\mathbb{Z}}_{2}$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the ${\mathbb{Z}}_{2}$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the ${\mathbb{Z}}_{2}$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. We discuss possible realizations of our model in real materials, in particular ${d}^{4}$ Mott insulators, and their potential applications.
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$\mathbbm{Z}_{2}$ topological quantum Paramagnet on a honeycomb bilayer
arXiv: Strongly Correlated Electrons, 2018Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a $\mathbbm{Z}_2$ topological quantum Paramagnet ({\em topological triplon insulator}) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial $\mathbbm{Z}_2$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the $\mathbbm{Z}_2$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the $\mathbbm{Z}_2$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. %the phase is characterized by a different topological invariant. We discuss possible realizations of our model in real materials, in particular d$^{4}$ Mott insulators, and their potential applications.
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mathbbm z _ 2 topological quantum Paramagnet on a honeycomb bilayer
Physical Review B, 2018Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a $\mathbbm{Z}_2$ topological quantum Paramagnet ({\em topological triplon insulator}) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial $\mathbbm{Z}_2$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the $\mathbbm{Z}_2$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the $\mathbbm{Z}_2$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. %the phase is characterized by a different topological invariant. We discuss possible realizations of our model in real materials, in particular d$^{4}$ Mott insulators, and their potential applications.
Gang Chen - One of the best experts on this subject based on the ideXlab platform.
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featureless quantum Paramagnet with frustrated criticality and competing spiral magnetism on spin 1 honeycomb lattice magnet
Physical Review Research, 2020Co-Authors: Jian Qiao Liu, Gang Chen, Ziqiang WangAbstract:This work study a spin-1 honeycomb lattice magnets with frustrated change interactions. The authors show the phase diagram of the model and emphasize the effects of magnetic frustration on magnetic excitations of featureless quantum Paramagnet.
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featureless quantum Paramagnet with frustrated criticality and competing spiral magnetism on spin 1 honeycomb lattice magnet
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Jian Qiao Liu, Gang Chen, Ziqiang WangAbstract:We study the spin-1 honeycomb lattice magnets with frustrated exchange interactions. The proposed microscopic spin model contains first and second neighbor Heisenberg interactions as well as the single-ion anisotropy. We establish a rich phase diagram that includes a featureless quantum Paramagnet and various spin spiral states induced by the mechanism of order by quantum disorder. Although the quantum Paramagnet is dubbed featureless, it is shown that, the magnetic excitations develop a contour degeneracy in the reciprocal space at the band minima. These contour degenerate excitations are responsible for the frustrated criticality from the quantum Paramagnet to the ordered phases. This work illustrates the effects of magnetic frustration on both magnetic orderings and the magnetic excitations. We discuss the experimental relevance to various Ni-based honeycomb lattice magnets.
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quantum Paramagnet and frustrated quantum criticality in a spin one diamond lattice antiferromagnet
Physical Review B, 2017Co-Authors: Gang ChenAbstract:Motivated by the very recent proposal of topological quantum Paramagnet in the diamond lattice antiferromagnet NiRh$_2$O$_4$, we propose a minimal model to describe the magnetic interaction and properties of the diamond material with the spin-one local moments. The minimal model includes the first and second neighbor Heisenberg interactions as well as a local single-ion spin anisotropy that is allowed by the spin-one nature of the local moment and the tetragonal symmetry of NiRh$_2$O$_4$ below 380K. We point out that there exists a quantum phase transition from a trivial quantum Paramagnet when the single-ion spin anisotropy is dominant to the magnetic ordered states when the exchange is dominant. Due to the frustrated spin interaction, the magnetic excitation in the quantum Paramagnetic state supports extensively degenerate band minima in the spectra. As the system approaches the transition, extensively degenerate bosonic modes become critical at the criticality, giving rise to unusual magnetic properties. Our phase diagram and experimental predictions for different phases provide a guildline for the identification of the ground state for NiRh$_2$O$_4$. Although our results are fundamentally different from the proposal of topological quantum Paramagnet for NiRh$_2$O$_4$, it represents interesting possibilities for spin-one diamond lattice antiferromagnets.
Tagirov M. - One of the best experts on this subject based on the ideXlab platform.
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Observation of magnetic coupling between the nuclei of liquid 3He and the 141Pr nuclei of PrF3 crystalline powder
2020Co-Authors: Egorov A., Irisov D., Klochkov A., Savinkov A., Safiullin K., Tagirov M., Tayurskii D., Yudin A.Abstract:The resonance magnetic coupling between the nuclei of liquid 3He and the 141Pr nuclei of a fine-dispersed powder of PrF3 Van Vleck Paramagnet with the grain size below 45 μm has been discovered at a temperature of 1.5 K with the use of a pulsed NMR technique. The magnetic specific heat of the corresponding spin systems is estimated theoretically. © 2007 Pleiades Publishing, Ltd
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Experimental proof of the existence of water clusters in fullerene-like PrF 3 nanoparticles
2020Co-Authors: Alakshin E., Klochkov A., Blokhin D., Sabitova A., Kono K., Korableva S., Tagirov M.Abstract:Synthesized fullerene-like nanoparticles of the Van Vleck Paramagnet PrF 3 have been studied by nuclear magnetic resonance cryoporometry. Water clusters have been discovered in the internal cavities of the nanoparticles. The analysis of the experimental data indicates that the cluster radius is 1-2. 3 nm. The obtained data agree well with the high-resolution transmission electron microscopy data. © 2012 Pleiades Publishing, Ltd
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Ultrahigh-frequency NMR of Tm3+ ions in single crystals of thulium ethylsulfate in high magnetic fields
2020Co-Authors: Abubakirov D., Tagirov M., Tayurskii D., Yudin A.Abstract:Resonant transitions predicted earlier between low-lying electron-nuclear sublevels of the Tm3+ ground state were observed at frequencies up to 700 MHz in a dielectric Van Vleck Paramagnet - thulium ethylsulfate single crystal. It is shown that, due to the distortion of the 4f-electron shell of a rare-earth ion in an applied magnetic field, the parameters of electron-nuclear interaction become field-dependent. © 2002 MAIK Nauka/Interperiodica"
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Size effect in the (PrF3 nanoparticles-3He) system
2020Co-Authors: Alakshin E., Klochkov A., Safiullin K., Sabitova A., Korableva S., Gazizulin R., Safin T., Tagirov M.Abstract:Spin kinetics of adsorbed and liquid 3He in contact with crystalline nanopowders of the Van Vleck Paramagnet PrF3 at a temperature of 1.5 K has been studied by nuclear magnetic resonance. The correlation between the parameters of the nuclear magnetic relaxation of 3He and the sizes of the sample particles has been found. A qualitative model of the magnetic relaxation of 3He describing the experimental results has been proposed. © 2013 Pleiades Publishing, Ltd
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Nuclear pseudoquadrupole resonance of 141Pr in Van Vleck Paramagnet PrF3
2020Co-Authors: Alakshin E., Egorov A., Klochkov A., Korableva S., Aleksandrov A., Tagirov M.Abstract:Nuclear pseudoquadrupole resonance of 141Pr in Van Vleck Paramagnet PrF3 has been observed in singlecrystal and micro- and nanopowder samples at a temperature of 4.2 K. The spectra of nuclear pseudoquadrupole resonance of 141Pr, as well as the spin-spin and spin-lattice relaxation parameters, have been obtained. The parameters of the nuclear spin Hamiltonian have been determined. It has been found that the parameters of the crystal electric field in nanocrystals differ strongly from those in microcrystals. © 2011 Pleiades Publishing, Ltd
Darshan G. Joshi - One of the best experts on this subject based on the ideXlab platform.
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Z 2 topological quantum Paramagnet on a honeycomb bilayer
Physical Review B, 2019Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a time-reversal-symmetry protected ${\mathbb{Z}}_{2}$ topological quantum Paramagnet (topological triplon insulator) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial ${\mathbb{Z}}_{2}$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the ${\mathbb{Z}}_{2}$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the ${\mathbb{Z}}_{2}$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. We discuss possible realizations of our model in real materials, in particular ${d}^{4}$ Mott insulators, and their potential applications.
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$\mathbbm{Z}_{2}$ topological quantum Paramagnet on a honeycomb bilayer
arXiv: Strongly Correlated Electrons, 2018Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a $\mathbbm{Z}_2$ topological quantum Paramagnet ({\em topological triplon insulator}) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial $\mathbbm{Z}_2$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the $\mathbbm{Z}_2$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the $\mathbbm{Z}_2$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. %the phase is characterized by a different topological invariant. We discuss possible realizations of our model in real materials, in particular d$^{4}$ Mott insulators, and their potential applications.
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mathbbm z _ 2 topological quantum Paramagnet on a honeycomb bilayer
Physical Review B, 2018Co-Authors: Darshan G. Joshi, Andreas P. SchnyderAbstract:Topological quantum Paramagnets are exotic states of matter, whose magnetic excitations have a topological band structure, while the ground state is topologically trivial. Here we show that a simple model of quantum spins on a honeycomb bilayer hosts a $\mathbbm{Z}_2$ topological quantum Paramagnet ({\em topological triplon insulator}) in the presence of spin-orbit coupling. The excitation spectrum of this quantum Paramagnet consists of three triplon bands, two of which carry a nontrivial $\mathbbm{Z}_2$ index. As a consequence, there appear two counterpropagating triplon excitation modes at the edge of the system. We compute the triplon edge state spectrum and the $\mathbbm{Z}_2$ index for various parameter choices. We further show that upon making one of the Heisenberg couplings stronger, the system undergoes a topological quantum phase transition, where the $\mathbbm{Z}_2$ index vanishes, to a different topological quantum Paramagnet. In this case the counterpopagating triplon edge modes are disconnected from the bulk excitations and are protected by a chiral and a unitary symmetry. %the phase is characterized by a different topological invariant. We discuss possible realizations of our model in real materials, in particular d$^{4}$ Mott insulators, and their potential applications.
A Schenck - One of the best experts on this subject based on the ideXlab platform.
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μ sr frequency shifts in the van vleck Paramagnet prin3
Hyperfine Interactions, 1997Co-Authors: A Grayevsky, I Felner, T Tashma, N Kaplan, F N Gygax, A Amato, M Pinkpank, A SchenckAbstract:As part of an ongoing μ+SR study on cubic van‐Vleck Paramagnets of the PrM3 series ( M\ =\ In,Pb,Tl,Sn), in which the CEF level scheme varies systematically, we present preliminary static μ+SR results on a single crystal of PrIn3.
