Related papers: Real-time manifestation of strongly coupled spin a…
A spin nematic is a state which breaks spin SU(2) symmetry while preserving translational and time reversal symmetries. Spin nematic order can arise naturally from charge fluctuations of a spin stripe state. Focusing on the possible…
Transition-metal perovskite oxides exhibit a wide range of extraordinary but imperfectly understood phenomena. Charge, spin, orbital, and lattice degrees of freedom all undergo order-disorder transitions in regimes not far from where the…
We investigate the electron density distribution and the stability of stripe phases in the realistic two-band model with hopping elements between e_g orbitals at Ni sites on the square lattice, and compare these results with those obtained…
Charge ordering (CO) phenomena have been widely debated in strongly-correlated electron systems mainly regarding their role in high-temperature superconductivity. Here, we elucidate the structural and charge distribution in NdNiO$_{2}$ thin…
We consider the pair correlation functions of both the order parameter field and its square for phase ordering in the $O(n)$ model with nonconserved order parameter, in spatial dimension $2\le d\le 3$ and spin dimension $1\le n\le d$. We…
We probe the density-wave transition of the trilayer nickelate La$_4$Ni$_3$O$_{10}$ with polarization-resolved infrared spectroscopy. The low-energy electrodynamics is strongly anisotropic, with metallic in-plane and insulating out-of-plane…
We present a Coherent X-ray Diffraction study of the antiferrodistortive displacive transition of SrTiO$_3$, a prototypical example of a phase transition for which the critical fluctuations exhibit two length scales and two time scales.…
The phase diagram and the order parameters of the exactly solvable quantum 1D model are analysed. The model in its spin representation is the dimerized XY spin chain in the presence of uniform and staggered transverse fields. In the…
We examine the spin and charge excitations in antiferromagnetic iron pnictides by mean-field calculations with a random phase approximation in a five-band itinerant model. The calculated excitation spectra reproduce well spin-wave…
Commensurability effects for nickelates have been studied by the first neutron experiments on La5/3Sr1/3NiO4. Upon cooling, this system undergoes three successive phase transitions associated with quasi-two-dimensional (2D) commensurate…
Resonant X-ray scattering (RXS) is a spectroscopy where both the power of site selective diffraction and the power of local absorption spectroscopy regarding atomic species are combined. By virtue of the dependence on the core level state…
We report resonant x-ray scattering data of the orbital and magnetic ordering at low temperatures at the Mn $L_{\rm 2,3}$ edges in \lsmo. The orderings display complex energy features close to the Mn absorption edges. Systematic modeling…
The spin dynamics of the S=1 Ni-chains in mixed-spin antiferromagnets Pr_2 Ba Ni O_5 and Nd_x Y_2-x Ba Ni O_5 is described in terms of a simple Ginzburg-Landau Lagrangian coupled to the sublattice of rare-earth ions. Within this framework…
Linear-chain nickelates with the composition (Nd_x Y_{1-x})_2 Ba Ni O_5 (x=1, x=0.75, x=0.5, and x=0.25) are studied in a series of neutron scattering experiments. Powder diffraction is used to determine the temperature dependence of the…
We study domain coarsening of two dimensional stripe patterns by numerically solving the Swift-Hohenberg model of Rayleigh-Benard convection. Near the bifurcation threshold, the evolution of disordered configurations is dominated by grain…
The cuprate superconductors exhibit ubiquitous instabilities toward charge-ordered states. These unusual electronic states break the spatial symmetries of the host crystal, and have been widely appreciated as essential ingredients for…
There have been two different proposals for the spin-triplet order parameter of the superconducting phase in Sr$_2$RuO$_4$; an $f$-wave order parameter and the multigap model where some of the bands have the line node. In an effort to…
We explore the spin states in the quantum spin chain compound SrCo$_{2}$V$_{2}$O$_{8}$ up to 14.9 T and down to 50 mK, using single-crystal neutron diffraction. Upon cooling in zero-field, antiferromagnetic (AFM) order of N\'eel type…
We propose an approach to probe coherent spin-state dynamics of molecules using circularly polarized hard x-ray pulses. For the dynamically aligned nitric oxide molecules in a coherent superposition spin-orbit coupled electronic state that…
We report nuclear magnetic resonance data in the bilayer nickelate La3Ni2O6. This material belongs to a family of low valence nickel oxides with square planar coordination of the Ni ions and is isoelectronic to the high temperature…