相关论文: Magnetic Excitations in the S=1/2 Alternating Chai…

Magnetic excitations in an array of (VO)2P2O7 single crystals have been measured using inelastic neutron scattering. Until now, (VO)2P2O7 has been thought of as a two-leg antiferromagnetic Heisenberg spin ladder with chains running in the…

In this letter we report results from inelastic neutron scattering experiments on powder samples of vanadyl pyrophosphate, (VO)2P2O7. We see evidence for three magnetic excitations, at 3.5 meV, 6.0 meV and 14 meV. The intensity of the 3.5…

Neutron-scattering experiments on (VO)_2P_2O_7 reveal both a gapped magnon dispersion and an unexpected, low-lying second mode. The proximity and intensity of these modes suggest a frustrated coupling between the alternating spin chains. We…

Nuclear magnetic resonance (NMR) of 31P and 51V nuclei has been measured in a spin-1/2 alternating-chain compound (VO)_2P_2O_7. By analyzing the temperature variation of the 31P NMR spectra, we have found that (VO)_2P_2O_7 has two…

Detailed experiments on single-crystal (VO)_2P_2O_7 continue to reveal new and unexpected features. We show that a model composed of two, independent planes of spin chains with frustrated magnetic coupling is consistent with nuclear…

Magnetic excitations have been investigated in the spin dimer material VODPO_4 \cdot 1/2 D_2O using inelastic neutron scattering. A dispersionless magnetic mode was observed at an energy of 7.81(4) meV. The wavevector dependence of the…

We present results from an inelastic neutron scattering experiment on the candidate Heisenberg spin ladder vanadyl pyrophosphate, (VO)2P2O7. We find evidence for a spin-wave excitation gap of $E_{gap} = 3.7\pm 0.2$ meV, at a band minimum…

Single crystals of the spin-gap system $\rm (VO)_2P_2O_7$ have been investigated by means of Raman scattering. At temperatures below T=75 K~$\approx 2\Delta_{01}({\bf k}=0)$, with $\Delta_{01}$ the singlet-triplet gap, a shoulder appears at…

Recent inelastic neutron scattering experiments on (VO)_2P_2O_7 (VOPO) have seen previously unanticipated sharp peaks in the dynamic structure factor in addition to the pair of triplet modes observed earlier. We argue that the additional…

We examine the magnetic field dependent excitations of the dimerized spin-1/2 chain, copper nitrate, with antiferromagnetic intra-dimer exchange $J_1=0.44$ meV and exchange alternation $\alpha=J_2/J_1=0.24$. Magnetic excitations in three…

Inelastic neutron scattering is used to identify single-particle and continuum spin excitations in the quasi-one-dimensional $S=1/2$ antiferromagnet \ba. In the data analysis, close attention is given to resolution effects. A gap in the…

We report magnetization and neutron scattering measurements of the half-doped compound La$_{1.5}$Sr$_{0.5}$CoO$_4$, which exhibits a checkerboard pattern of charge ordering below ~800K. In the antiferromagnetically-ordered phase below \~40K…

We have explored the magnetic excitation spectrum of the S=1/2 square lattice Heisenberg antiferromagnet, K2V3O8 using both triple-axis and time-of-flight inelastic neutron scattering. The long-wavelength spin waves are consistent with the…

Experimental results on magnetic resonance (ESR) and magnetic susceptibility are given for single crystalline (VO)$_2$P$_2$O$_{7}$. The crystal growth procedure is briefly discussed. The susceptibility is interpreted numerically using a…

Motivated by recent measurements on CuGeO$_3$ the spectrum of magnetic excitations of an antiferromagnetic $S=\frac{1}{2}$ chain with alternating coupling strength is investigated. Wave vector dependent magnons and a continuum with square…

Inelastic neutron scattering is used to study transverse-polarized magnetic excitations in the quasi-one-dimensional S=1/2 antiferromagnet BaCu_2Si_2O_7, where the saturation value for the N\'eel order parameter is $m_0=0.12 \mu_{\rm B}$…

We investigate magnetic excitations in the frustrated zigzag spin-1/2 chain compound $\beta$-TeVO$_4$ by inelastic neutron scattering. In the magnetically ordered ground state, the excitation spectrum exhibits coexisting magnon dispersion,…

Single crystal neutron diffraction, inelastic neutron scattering and electron spin resonance experiments are used to study the magnetic structure and spin waves in Pb$_2$VO(PO$_4$)$_2$, a prototypical layered $S=1/2$ ferromagnet with…

We have synthesized single-crystal samples of $\beta$-VOSO$_4$ and fully characterized their magnetic properties. Our magnetic susceptibility, high field magnetization and powder inelastic neutron scattering results are in excellent…

The magnetic susceptibilities chi versus temperature T of powders and single crystals of the ambient-pressure (AP) and high-pressure (HP) phases of (VO)_{2}P_{2}O_{7} are analyzed using an accurate theoretical prediction of chi(T, J1, J2)…