Related papers: Soft Modes and Relaxor Ferroelectrics
The excitation of soft dipole modes in light nuclei via inelastic electron scattering is investigated. I show that, under the proposed conditions of the forthcoming electron-ion colliders, the scattering cross sections have a direct…
We present evidence for a novel finite-temperature phase transition in the phason elasticity of quasicrystals. A tiling model for energetically stabilized decagonal quasicrystals has been studied in an extensive series of Monte Carlo…
The Bialas-Bzdak model of elastic proton-proton scattering is generalized to the case when the real part of the parton-parton level forward scattering amplitude is non-vanishing. Such a generalization enables the model to describe well the…
Soft phonons and diffuse scattering in insulating La$_{2-x}$Sr$_{x}$CuO$_4$ ($x=0.05$) have been studied by the neutron scattering technique. The X-point phonon softens from high temperature towards the structural transition temperature…
Polarized neutron inelastic scattering has been used to measure spin excitations in ferromagnetic La$_{0.82}$Sr$_{0.18}$CoO$_{3}$. The magnon spectrum of these spin excitations is well defined at low energies but becomes heavily damped at…
We studied the diffusion coefficient of hot electrons of GaN crystals in moderate electric (1...10 kV/cm) and magnetic (1...4 T) fields. Two configurations, parallel and crossed fields, are analysed. The study was carried out for…
We consider frequency dependence of the neutron scattering amplitude from a two-dimensional quantum antiferromagnet. It is well known that the long range order disappears at any finite temperature and hence the elastic neutron scattering…
We have investigated the quasiparticle dynamics and collective excitations in the quasi-one-dimensional material ZrTe$_5$ using ultrafast optical pump-probe spectroscopy. Our time-domain results reveal two coherent oscillations having…
We present a neutron scattering study of phonons in single crystals of (Pb$_{0.5}$Sn$_{0.5}$)$_{1-x}$In$_x$Te with $x=0$ (metallic, but nonsuperconducting) and $x=0.2$ (nonmetallic normal state, but superconducting). We map the phonon…
We study inelastic neutrino scattering off hot nuclei for temperatures relevant under supernova conditions. The method we use is based on the quasiparticle random phase approximation extended to finite temperatures within the thermo field…
We have analyzed low-temperature behavior of two-dimensional electron gas in polar heterostructures subjected to a high electric field. When the optical phonon emission is the fastest relaxation process, we have found existence of…
The pressure-temperature phase diagram of the heavy-electron superconductor URu2Si2 has been reinvestigated by ac-susceptibility and elastic neutron-scattering (NS) measurements performed on a small single-crystalline rod (2 mm in diameter,…
Transient responses of the electronic excitation and coherent soft phonon are investigated both above and below the ferroelectric phase transition temperature T$_{c}$ in Pb$_{1-x}$Ge$_{x}$Te by using an optical pump-probe technique. The…
Separating out the contributions of different scattering channels in strongly interacting metals is crucial in identifying the mechanisms that govern their properties. While momentum or current relaxation rates can be readily probed via…
Materials undergoing antiferroelectric/ferroelectric (AFE/FE) transitions are studied for possible applications that exploit the large volume, charge and entropy differences between the two states, such as electrocaloric cooling, energy…
Hard sphere suspensions are well recognized model systems of statistical physics and soft condensed matter. We here investigate the temporal evolution of the immediate environment of nucleating and growing crystals and/or their global scale…
The existence of polar nanoregions is the most important characteristic of ferroelectric relaxors, however, the size determination and dynamic of PNRs remains uncertain. We reveal a re-entrant relaxor behavior and ferroelectric-paraelectric…
A quasi-spin Ising model of ferroelastic phase transition is developed and employed to perform atomic-scale Monte Carlo simulation of thermoelastic martensitic transformation. The quasi-spin variable associated with the lattice sites…
The magnetic order, spin dynamics, and crystal structure of the multiferroic Sr0.56Ba0.44MnO3 have been investigated using neutron and x-ray scattering. Ferroelectricity develops at TC=305 K with a polarization of 4.2 microC/cm2 associated…
The path probability method (PPM) in the tetrahedron-cactus approximation is applied to the Slater-Takagi model with dipole-dipole interaction for KH2PO4-type hydrogen-bonded ferroelectric crystals in order to derive a small dip structure…