Related papers: Optical observation of quasiperiodic Heisenberg an…
The spin-wave excitation spectrum, the magnetization, and the N\'{e}el temperature for the quasi-two-dimensional spin-1/2 antiferromagnetic Heisenberg model with compass-model interaction in the plane proposed for iridates are calculated in…
Magnetic and lattice excitations in the quantum antiferromagnet (C$_4$H$_{12}$N$_2$)Cu$_2$Cl$_6$ (PHCC) are studied across two pressure-induced phase transition at $P_c=4.3~\mathrm{kbar}$ and $P_1=13.4~\mathrm{kbar}$ using Raman…
Recent neutron scattering experiments have revealed that the generic form of the magnetic excitations in the high-Tc cuprates of wide range of doping has the so-called "hourglass" shape; it features both upward and downward excitations at…
We report an extraordinary pressure dependence of the magnetic interactions in the metal-organic system [(CuF$_2$(H$_2$O)$_2$)$_2$pyrazine]. At zero pressure, this material realizes a quasi-two-dimensional (Q2D) spin-1/2 square-lattice…
The Heisenberg model for S=1/2 describes the interacting spins of electrons localized on lattice sites due to strong repulsion. It is the simplest strong-coupling model in condensed matter physics with wide-spread applications. Its…
We consider a two-layer Heisenberg antiferromagnet which can be either in the N\'{e}el-ordered or in the disordered phase at $T=0$, depending on the ratio of the intra- and interlayer exchange constants. We reduce the problem to an…
We consider ultracold matter of spin-2 atoms in optical lattices. We derive an effective Hamiltonian for the studies of spin ordering in Mott states and investigate hyperfine spin correlations. Particularly, we diagonalize the Hamiltonian…
The antiferromagnetic Heisenberg model is studied on a two-dimensional bipartite quasiperiodic lattice. The distribution of local staggered magnetic moments is determined on finite square approximants with up to 1393 sites, using the…
Atomically thin MoS$_{2}$ crystals have been recognized as a quasi-2D semiconductor with remarkable physics properties. This letter reports our Raman scattering measurements on multilayer and monolayer MoS$_{2}$, especially in the…
Inelastic light scattering from electrons is a symmetry-selective probe of the charge dynamics within correlated materials. Many measurements have been made on correlated insulators, and recent exact solutions in large dimensions explain a…
A quantitative description of magnons in long-range ordered quantum antiferromagnets is presented which is consistent from low to high energies. It is illustrated for the generic $S=1/2$ Heisenberg model on the square lattice. The approach…
We propose an effective model to describe the $A_{2g}$ signal in Raman scattering experiments in the URu$_{2}$Si$_{2}$ compound. We follow the scheme proposed earlier by Khveshchenko and Wiegmann [Phys. Rev. Lett. 73, 500 (1994)] to…
We used a combination of polarized Raman spectroscopy and spin wave calculations to study magnetic excitations in the strong spin-orbit-coupled (SOC) bilayer perovskite antiferromagnet $Sr_3Ir_2O_7$. We observed two broad Raman features at…
Raman scattering experiments on CdCr2S4 single crystals show pronounced anomalies in intensity and frequency of optical phonon modes with an onset temperature T*=130 K that coincides with the regime of giant magnetocapacitive effects. A…
We use the matrix product state formalism to construct stationary scattering states of elementary excitations in generic one-dimensional quantum lattice systems. Our method is applied to the spin-1 Heisenberg antiferromagnet, for which we…
We investigate effects of pseudo-spin population imbalance on Mott phases in 1D trapped two-component atomic Fermi gases loaded on optical lattices based on the repulsive Hubbard model in harmonic traps. By using the density matrix…
The interplay of magnetic excitations and itinerant charge carriers is a ubiquitous phenomenon in strongly correlated electron systems. In the vicinity of magnetically ordered phases, strong interactions between itinerant quasiparticles and…
Nature creates electrons with two values of the spin projection quantum number. In certain applications, it is important to filter electrons with one spin projection from the rest. Such filtering is not trivial, since spin-dependent…
Based on micromagnetic theory we have derived analytical expressions for the magnetic small-angle neutron scattering (SANS) cross section of a two-phase particle-matrix-type ferromagnet. The approach---valid close to magnetic…
We investigate the influence of an interband exchange interaction on magnetism in a two-band Hubbard model. Our main emphasis lies on spin-flip scattering which is often neglected but is neccessary to retain the full rotational symmetry of…