928 research outputs found
Field-Induced Gap in a Quantum Spin-1/2 Chain in a Strong Magnetic Field
Magnetic excitations in copper pyrimidine dinitrate, a spin-1/2
antiferromagnetic chain with alternating -tensor and Dzyaloshinskii-Moriya
interactions that exhibits a field-induced spin gap, are probed by means of
pulsed-field electron spin resonance spectroscopy. In particular, we report on
a minimum of the gap in the vicinity of the saturation field T
associated with a transition from the sine-Gordon region (with soliton-breather
elementary excitations) to a spin-polarized state (with magnon excitations).
This interpretation is fully confirmed by the quantitative agreement over the
entire field range of the experimental data with the DMRG investigation of the
spin-1/2 Heisenberg chain with a staggered transverse field
Structure and properties of Ti/TiB metal-matrix composite after isothermal multiaxial forging
Microstructure and mechanical properties of a Ti/TiB metal-matrix composites after multiaxial forging at 850°C to the true strain " = 5:2 were studied. The composite with 17 vol.% of TiB was produced via spark plasma sintering at 1000°
ESR modes in a Strong-Leg Ladder in the Tomonaga-Luttinger Liquid Phase
Magnetic excitations in the strong-leg quantum spin ladder compound
(CHN)CuBr (known as DIMPY) in the field-induced
Tomonaga-Luttinger spin liquid phase are studied by means of high-field
electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode
with unusual non-linear frequency-field dependence is revealed experimentally.
Using a combination of analytic and exact diagonalization methods, we compute
the dynamical structure factor and identify this mode with longitudinal
excitations in the antisymmetric channel. We argue that these excitations
constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2
Heisenberg antiferromagnetic ladder and owe its ESR observability to the
uniform Dzyaloshinskii-Moriya interaction
Establishing the fundamental magnetic interactions in the chiral skyrmionic Mott insulator Cu2OSeO3 by terahertz electron spin resonance
The recent discovery of skyrmions in CuOSeO has established a new
platform to create and manipulate skyrmionic spin textures. We use high-field
electron spin resonance (ESR) spectroscopy combining a terahertz free electron
laser and pulsed magnetic fields up to 64 T to probe and quantify its
microscopic spin-spin interactions. Besides providing direct access to the
long-wavelength Goldstone mode, this technique probes also the high-energy part
of the excitation spectrum which is inaccessible by standard low-frequency ESR.
Fitting the behavior of the observed modes in magnetic field to a theoretical
framework establishes experimentally that the fundamental magnetic building
blocks of this skyrmionic magnet are rigid, highly entangled and weakly coupled
tetrahedra.Comment: 5 pages, 3 Figure
Mechanical behavior and microstructure evolution of a Ti-15Mo/TiB titanium–matrix composite during hot deformation
A Ti-15Mo/TiB titanium–matrix composite (TMC) was produced by spark plasma sintering at 1400◦C under a load of 40 MPa for 15 min using a Ti-14.25(wt.)%Mo-5(wt.)%TiB2 powder mixture. Microstructure evolution and mechanical behavior of the composite were studied during uniaxial compression at room temperature and in a temperature range of 500–1000◦C
Microstructure evolution of a ti/tib metal-matrix composite during high-temperature deformation
A Ti/TiB metal-matrix composite (MMC) was produced by spark plasma sintering using a Ti-10wt.%TiB2 powder mixture at 850°C under a load of 40 MPa for 15 min. The microstructure evolution and mechanical behavior of the Ti/TiB composite during uniaxial compression at the temperature range 500 - 1050°С was studie
Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet CsCuBr
We report on high-field electron spin resonance (ESR) studies of magnetic
excitations in the spin-1/2 triangular-lattice antiferromagnet CsCuBr.
Frequency-field diagrams of ESR excitations are measured for different
orientations of magnetic fields up to 25 T. We show that the substantial
zero-field energy gap, K, observed in the low-temperature
excitation spectrum of CsCuBr [Zvyagin , Phys. Rev. Lett. 112,
077206 (2014)], is present well above . Noticeably, the transition into
the long-range magnetically ordered phase does not significantly affect the
size of the gap, suggesting that even below the high-energy spin dynamics
in CsCuBr is determined by short-range-order spin correlations. The
experimental data are compared with results of model spin-wave-theory
calculations for spin-1/2 triangle-lattice antiferromagnet.Comment: 6 pages, 9 figure
THz-range free-electron laser ESR spectroscopy: techniques and applications in high magnetic fields
The successful use of picosecond-pulse free-electron-laser (FEL) radiation
for the continuous-wave THz-range electron spin resonance (ESR) spectroscopy
has been demonstrated. The combination of two linac-based FELs (covering the
wavelength range of 4 - 250 m) with pulsed magnetic fields up to 70 T
allows for multi-frequency ESR spectroscopy in a frequency range of 1.2 - 75
THz with a spectral resolution better than 1%. The performance of the
spectrometer is illustrated with ESR spectra obtained in the
2,2-diphenyl-1-picrylhydrazyl (DPPH) and the low-dimensional organic material
(CHN)CuCl.Comment: 9 pages, 9 figures. Rev. Sci. Instrum., accepte
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