Related papers: Quantum spin chain as a potential realization of t…
The macroscopic magnetic characterization of the Mn(II) - nitronyl nitroxide free radical chain (Mn(hfac)2(R)-3MLNN) evidenced its transition from a 1-dimensional behavior of ferrimagnetic chains to a 3-dimensional ferromagnetic long range…
We report on a heat capacity study of high quality single crystal samples of \lcvo\ -- a frustrated spin $S=1/2$ chain system -- in magnetic field amounting to 3/4 of the saturation field. At low fields up to about 7~T, a linear temperature…
We study spin-$1/2$ chains with long-range power-law decaying unfrustrated (bipartite) Heisenberg exchange $J_r \propto r^{-\alpha}$ and multi-spin interactions $Q$ favoring a valence-bond solid (VBS) ground state. Employing quantum Monte…
A Heisenberg model over the square lattice recently introduced by Si and Abrahams to describe local-moment magnetism in the new class of Fe-As high-Tc superconductors is analyzed in the classical limit and on a small cluster by exact…
We present a theoretical and experimental study of a quasi-one-dimensional zigzag antiferromagnet (N_2H_5)CuCl_3, which can be viewed as weakly coupled Heisenberg chains with a frustrated interaction. We first discuss generic features of…
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…
Muon spin rotation technique is used to study magnetic ordering in ultra-pure samples of SrCu$_{1-x}$Ni$_x$O$_2$, an archetypical $S=1/2$ antiferromagnetic Heisenberg chain system with a small amount of $S=1$ defects. The ordered state in…
We present neutron diffraction, muon spin rotation and pulsed-field magnetometry measurements on the Heisenberg quantum chiral chain [Cu(pym)(H2O)4]SiF6.H2O, which displays a four-fold-periodic rotation of the local environment around the…
The $S=1/2$, nearest-neighbor, quantum Heisenberg antiferromagnet on the square lattice with spatially anisotropic couplings is reconsidered, with particular attention to the following question: at T=0, does N\'eel orderdevelop at…
We present a combined experimental and theoretical study of the spin-1/2 compound CuP$_2$O$_6$ that features a network of two-dimensional (2D) antiferromagnetic (AFM) square planes, interconnected via one-dimensional (1D) AFM spin chains.…
Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu$_2$O$_2$, a $S=1/2$ spin-chain compound with competing interactions. The magnetic structure is found to be helimagnetic,…
The Heisenberg XXZ spin-1/2 chain is considered in the massive antiferromagnetic regime in the presence of a staggered longitudinal magnetic field. The Hamiltonian of the model is characterised by the anisotropy parameter $\Delta<-1$, and…
The one-dimensional transverse Ising model is a paradigmatic example of quantum criticality. In spin-orbit coupled systems, however, effective Ising interactions arise alongside bond-dependent couplings such as Kitaev ($K$) and $\Gamma$…
We study weakly coupled antiferromagnetic spin chains in their ordered phase by combinining an exact solution of the single-chain problem with an RPA analysis of the interchain interaction. A single chain is described by a quantum…
We study the ground-state properties of a spin-1/2 model on a chain containing four-spin Ising-like interactions in the presence of both transverse and longitudinal magnetic fields. We use entanglement entropy and finite-size scaling…
We study the effects of weak long-ranged antiferromagnetic interactions of strength $Q$ on a spin model with predominant short-ranged ferromagnetic interactions. In three dimensions, this model exhibits an avoided critical point in the…
Inelastic neutron scattering is employed to study transverse spin correlations of a Heisenberg $S=1/2$ chain compound in a magnetic field of 7.5 T. The target compound is the antiferromagnetic Heisenberg $S=1/2$ chain material…
A compound with very weakly interacting chains, MnCl$_3$(bpy), has attracted a great deal of attention as a possible $S=2$ Haldane chain. However, long-range magnetic order of the chains prevents the Haldane gap from developing below…
A model is introduced describing the interplay between superconductivity and spin-ordering. It is characterized by on-site repulsive electron-electron interactions, causing antiferromagnetism, and nearest-neighbor attractive interactions,…
We present a detailed powder and single crystal neutron diffraction study of the spin chain compound Ca3Co2O6. Below 25 K, the system orders magnetically with a modulated partially disordered antiferromagnetic structure. We give a…