5 research outputs found
Observation of Antiferroelectric Domain Walls in a Uniaxial Hyperferroelectric
Ferroelectric domain walls are a rich source of emergent electronic
properties and unusual polar order. Recent studies showed that the
configuration of ferroelectric walls can go well beyond the conventional
Ising-type structure. N\'eel-, Bloch-, and vortex-like polar patterns have been
observed, displaying strong similarities with the spin textures at magnetic
domain walls. Here, we report the discovery of antiferroelectric domain walls
in the uniaxial ferroelectric PbGeO. We resolve highly
mobile domain walls with an alternating displacement of Pb atoms, resulting in
a cyclic 180 flip of dipole direction within the wall. Density
functional theory calculations reveal that PbGeO is
hyperferroelectric, allowing the system to overcome the depolarization fields
that usually suppress antiparallel ordering of dipoles along the longitudinal
direction. Interestingly, the antiferroelectric walls observed under the
electron beam are energetically more costly than basic head-to-head or
tail-to-tail walls. The results suggest a new type of excited domain-wall
state, expanding previous studies on ferroelectric domain walls into the realm
of antiferroic phenomena
Molecular mechanism for opioid dichotomy: bidirectional effect of μ-opioid receptors on P2X3 receptor currents in rat sensory neurones
Study of strange matter production in the heavy ion collisions at NUCLOTRON
It is proposed to install an experimental setup in the fixed-target hall of the Nuclotron with the final goal to perform a research program focused on the production of strange matter in heavyion collisions at beam energies between 2 and 6 A GeV. The basic setup will comprise a large acceptance dipole magnet with inner tracking detector modules based on double-sided Silicon micro-strip sensors and GEMs. The outer tracking will be based on the drift chambers and straw tube detector. Particle identification will be based on the time-of-flight measurements. This setup will be sufficient perform a comprehensive study of strangeness production in heavy-ion collisions, including multi-strange hyperons, multi-strange hypernuclei, and exotic multi-strange heavy objects. These pioneering measurements would provide the first data on the production of these particles in heavy-ion collisions at Nuclotron beam energies, and would open an avenue to explore the third (strangeness) axis of the nuclear chart. The extension of the experimental program is related with the study of in-medium effects for vector mesons decaying in hadronic modes. The studies of the NN and NA reactions for the reference is assumed