Related papers: Spinons, solitons and random singlets in the spin-…
We report macroscopic magnetic measurements carried out in order to detect and characterize field-induced quantum entanglement in low dimensional spin systems. We analyze the pyroborate MgMnB_2O_5 and the and the warwickite MgTiOBO_3,…
The nature of quantum spin liquids is studied for the spin-$1/2$ antiferromagnetic Heisenberg model on a square lattice containing exchange interactions between nearest-neighbor sites, $J_1$, and those between next-nearest-neighbor sites,…
Combining quantum Monte Carlo simulations with the maximum entropy method, we study the dynamical structure factor $S(k,\omega)$ of spin-1/2 antiferromagnetic Heisenberg chains with various random bond distributions. We emphasize the…
Using the density-matrix renormalization group technique, we study a one-dimensional spin-$\frac{1}{2}$ Heisenberg chain consisting of coupled tetramers as an effective spin model for copper vanadate CuInVO$_5$. We obtain the ground-state…
Observing constituent particles with fractional quantum numbers in confined and deconfined states is an interesting and challenging problem in quantum many-body physics. Here we further explore a computational scheme [Y. Tang and A. W.…
Heisenberg-type spin-chain materials have been extensively studied over the years, yet not much is known about their behavior in the presence of disorder. Starting from BaCu$_2$Si$_2$O$_7$, a typical spin-1/2 chain system, we investigate a…
Magnetic, thermodynamic, neutron diffraction and inelastic neutron scattering are used to study spin correlations in the easy-axis XXZ triangular lattice magnet K2Co(SeO3)2. Despite the presence of quasi-2D "supersolid" magnetic order, the…
Spin transport properties of the one-dimensional Heisenberg antiferromagnetic spin systems for both $S=1/2$ and S=1 are studied by applying twisted boundary magnetic field. The spin current displays significantly different behavior of the…
The magnetic state of the single-component molecular compound, [Cu(tmdt)$_{2}$], is investigated by means of $^{1}$H-NMR. An abrupt spectral broadening below 13 K and a sharp peak in nuclear spin-lattice relaxation rate, $T_{1}^{-1}$, at 13…
We investigate theoretically the spiral staircase Heisenberg spin-$1/2$ ladder in the presence of antiferromagnetic long-range spin interactions and a uniform magnetic field. As a special case we also consider the Kondo necklace model. If…
We present combined experimental and theoretical investigation of the low-frequency ESR dynamics in the ordered phases of magnetic mineral linarite. This material consists of weakly coupled spin-1/2 chains of copper ions with frustrated…
We discuss collective spin wave excitations in triplet superconductors with an easy axis anisotropy for the order parameter. Using a microscopic model for interacting electrons we estimate the frequency of such excitations in Bechgaard…
The magnetic insulator copper pyrazine dinitrate comprises antiferromagnetic spin-1/2 chains that are well described by the exactly solvable one-dimensional Heisenberg model, providing a unique opportunity for a quantitative comparison…
We report the magnetic excitation spectrum as measured by inelastic neutron scattering for a polycrystalline sample of Sr$_3$CuPtO$_6$. Modeling the data by the 2+4 spinon contributions to the dynamical susceptibility within the chains, and…
Low-lying excited states as well as the ground state of the spin-1 antiferromagnetic Heisenberg chain with a spin-1/2 impurity are studied by means of a method of numerical diagonalization. The isotropic nearest-neighbor exchange coupling…
Quantum spin liquids are highly entangled magnetic states with exotic properties. The $S = 1/2$ square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin…
Inelastic neutron scattering is used to identify single-particle and continuum spin excitations in the quasi-one-dimensional $S=1/2$ antiferromagnet \ba. In the data analysis, close attention is given to resolution effects. A gap in the…
The search for the experimental evidence of quantum spin liquid (QSL) states is critical but extremely challenging, as the quenched interaction randomness introduced by structural imperfection is usually inevitable in real materials.…
Experimental quest for the hypothetical "quantum spin liquid" state has recently met a few promising candidate materials including organic salts \kappa-(ET)2Cu2(CN)3 and EtMe3Sb[Pd(dmit)2]2, S=1/2 triangular-lattice Heisenberg…
We study the spin-half Heisenberg chain with alternating nearest neighbor interactions $J_1(1+\delta)$ and $J_1(1-\delta)$ and a uniform second neighbor interaction $J_2=y (1-\delta)$ by series expansions around the limit of decoupled…