Related papers: Low-energy excitations in NaV2O5
Inelastic neutron scattering measurements mapping the in-plane magnetic interactions of Na0.5CoO2 reveal dispersive excitations at points above an energy gap Eg = 11.5(5) meV at the superstructural Bragg reflections. The excitations are…
We investigate the temperature dependent optical properties of NaV2O5, in the energy range 4meV-4eV. The symmetry of the system is discussed on the basis of infrared phonon spectra. By analyzing the optically allowed phonons at temperatures…
Inelastic neutron scattering experiments with a large set of comounted Na$_2$IrO$_3$ crystals reveal the low-energy magnon dispersion in this candidate material for Kitaev physics. The magnon gap amounts to 1.7(1) meV and can be interpreted…
Inelastic neutron scattering measurements on single crystals of superconducting BaFe1.84Co0.16As2 reveal a magnetic excitation located at wavevectors (1/2 1/2 L) in tetragonal notation. On cooling below TC, a clear resonance peak is…
We present single-mode nanowire (NW) lasers with ultralow threshold in the near-infrared spectral range. To ensure the single-mode operation, the NW diameter and length are reduced specifically to minimize the longitudinal and transverse…
Properties of low-dimensional spin-Peierls systems are described by using a one dimensional S=1/2 antiferromagnetic Heisenberg chain linearly coupled to a single phonon mode of wave vector pi (whose contribution is expected to be dominant).…
Low-energy dipole (LED) excitations in $^{20}$O were investigated by variation after $K$-projection of deformation($\beta$)-constraint antisymmetrized molecular dynamics combined with the generator coordinate method. We obtained two LED…
This paper reports on the spin glass-like coexistence of competing magnetic orders in oxygen-deficient V2O5 nanoparticles having a broad size distribution. X-ray photoelectron spectroscopy yields the surface chemical stoichiometry of nearly…
We study the energy-momentum relations of the Nambu-Goldstone modes in quantum antiferromagnetic Heisenberg models on a hypercubic lattice. This work is a sequel to the previous series about the models. We prove that the Nambu-Goldstone…
We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na(0.3)CoO(2).1.3H(2)O. The electronic contribution to the specific heat, gamma, is found to be 12.2 mJ/mol-K2. The feature at the…
Phase separation of metallic and antiferromagnetic (AFM) insulating phases in alkaline iron selenides (AxFe2-ySe2) continues to attract intense interest because the relationship between two peculiar features probably is a key to clarifying…
Charged particle and gamma decays in 24Mg* are investigated for excitation energies where quasimolecular resonances appear in 12C+12C collisions. Various theoretical predictions for the occurence of superdeformed and hyperdeformed bands…
We report inelastic light scattering experiments on superconductor Ce0.6Y0.4FeAsO0.8F0.2 from 4K to 300K covering the superconducting transition temperature Tc ~ 48.6K. A strong evidence of the superconductivity induced phonon…
UV Raman scattering studies show longitudinal optical (LO) mode up to 4th order in wurtzite GaN nanowire system. Frohlich interaction of electron with the long range electrostatic field of ionic bonded GaN gives rise to enhancement in LO…
Advanced synchrotron radiation focusing down to a size of 300 nm has been used to visualize nanoscale phase separation in the K0.8Fe1.6Se2 superconducting system using scanning nanofocus single-crystal X-ray diffraction. The results show an…
We study with the Raman scattering technique two types of phase transitions in the pyroxene compounds NaMSi$_2$O$_6$ (with M=Ti, V, and Cr). In the quasi one-dimensional S=1/2 system NaTiSi$_2$O$_6$ we observe anomalous high-temperature…
Polarized Raman scattering spectra of superconducting K$_x$Fe$_{2-y}$Se$_2$ and nonsuperconducting K$_{0.8}$Fe$_{1.8}$Co$_{0.2}$Se$_2$ single crystals were measured in a temperature range from 10 K up to 300 K. Two Raman active modes from…
Phase diagram of Na$_x$CoO$_2$ (x $\gtrsim$ 0.71) has been reinvestigated using electrochemically fine tuned single crystals. Both phase separation and staging phenomena as a result of sodium multi-vacancy cluster ordering have been found.…
$R_2BaNiO_5$ ($R=$ rare earth) quasi-1-D antiferromagnets are structurally equivalent to the well-studied 1-D S=1 Haldane-gap compound Y_2BaNiO_5. Unlike the Y-nickelate though, these materials undergo 3-D magnetic ordering at finite…
We performed 23Na NMR and magnetization measurements on an S = 1, quasi-2D honeycomb lattice antiferromagnet Na3Ni2BiO6. A large positive Curie-Weiss constant of 22.9 K is observed. The NMR spectra at low fields are consistent with a…