Related papers: Order by distortion and string modes in pyrochlore…
Exotic state of matter could coexist with conventional orders such that the gauge fields and fractionalized excitations could prevail in a seemingly ordered state. We explore the Coulombic antiferromagnet in the spin-1/2 pyrochlores with…
We show that strong electromagnon peaks can be found in absorption spectra of non-collinear magnets exhibiting a linear magnetoelectric effect. The frequencies of these peaks coincide with the frequencies of antiferromagnetic resonances and…
We show that triangle-based antiferromagnets with "anti-chiral" order display a non-trivial dependence of the spin orientation with an in-plane field. The spins evolve from rotating in the opposite sense to the field at very low fields to…
We study numerically the one-dimensional Kondo and Hund lattices consisting of localized spins interacting antiferro or ferromagnetically with the itinerant electrons, respectively. Using the Density Matrix Renormalization Group we find,…
Stimulated by recent studies of quantum phases with broken local inversion symmetry, we study the magnetoelectric effect in locally noncentrosymmetric metals. We consider three-dimensional (3D) coupled zigzag chains and demonstrate that the…
We study the spin-1 chain with nearest neighbor couplings that are rotationally invariant, but include both Heisenberg and biquadratic exchange, with random strengths. We demonstrate, using perturbative renormalization group methods as well…
The thermodynamics of the antiferromagnetic ordering transition in NiO and the photoelectron spectra in the antiferromagnetic phase are studied by the Variational Cluster Approximation. Using realistic Racah parameters to describe the…
Within Landau theory, magnetism and polarity are homotopic, displaying a one-to-one correspondence between most physical characteristics. However, despite widely reported noncollinear magnetism, spontaneous noncollinear electric dipole…
Extensive investigation has recently been conducted into a new class of antiferromagnetic order known as magnetic octupole order. However, the high rank of octupoles makes it difficult to detect and manipulate them by using conventional…
A series of Pr(TM)$_2$X$_{20}$ (with TM=Ti,V,Rh,Ir and X=Al,Zn) Kondo materials, containing non-Kramers Pr$^{3+}$ $4f^2$ moments on a diamond lattice, have been shown to exhibit intertwined orders such as quadrupolar order and…
The ground-state properties of the spin-1 antiferromagnetic Heisenberg model on the corner-sharing tetrahedra, pyrochlore lattice, is investigated. By breaking up each spin into a pair of 1/2-spins, the problem is reduced to the equivalent…
We analyze a model of itinerant electrons interacting through a quadrupole density-density repulsion in three dimensions. At the mean field level, the interaction drives a continuous Pomeranchuk instability towards $d$-wave, spin-triplet…
The XY-pyrochlore antiferromagnet \ETO\ is studied by heat capacity measurements and electron spin resonance spectroscopy performed on single crystal samples. The magnetic phase diagrams are established for two directions of applied field,…
We study the ground state and thermodynamic properties of the spin-half XXZ model, with an Ising interaction $J_z$ and a transverse exchange interaction $J_{x}$, on a pyrochlore tube obtained by joining together elementary cubes in a…
We have investigated the dielectric anomalies associated with spin ordering transitions in the tetragonal spinel Mn$_3$O$_4$, using thermodynamic, magnetic, and dielectric measurements. We find that two of the three magnetic ordering…
The interplay of disorder and spin-fluctuation effects in a disordered antiferromagnet is studied. In the weak-disorder regime (W \le U), while the energy gap decreases rapidly with disorder, the sublattice magnetization, including quantum…
The search for new quantum phases, especially in frustrated magnets, is central to modern condensed matter physics. One of the most promising places to look is in rare-earth pyrochlore magnets with highly-anisotropic exchange interactions,…
We evaluate the charge and longitudinal spin response functions of a two-dimensional electron gas with $e^2/r$ interactions in an arbitrary state of spin polarization, using a structurally self-consistent approach to treat exchange and…
Antiferromagnetism (AF) such as Neel ordering is often closely related to Coulomb interactions such as Hubbard repulsion in two-dimensional (2D) systems. Whether Neel AF ordering in 2D can be dominantly induced by electron-phonon couplings…
MgCr$_{2}$O$_{4}$ is one of the best-known realizations of the pyrochlore-lattice Heisenberg antiferromagnet. The strong antiferromagnetic exchange interactions are perturbed by small further-neighbor exchanges such that this compound may…