468 research outputs found
Microscopic evidence for field-induced magnetism in CeCoIn
We present NMR data in the normal and superconducting states of CeCoIn
for fields close to T in the plane. Recent
experiments identified a first-order transition from the normal to
superconducting state for T, and a new thermodynamic phase below 290
mK within the superconducting state. We find that the Knight shifts of the
In(1), In(2) and the Co are discontinuous across the first-order transition and
the magnetic linewidths increase dramatically. The broadening differs for the
three sites, unlike the expectation for an Abrikosov vortex lattice, and
suggests the presence of static spin moments in the vortex cores. In the
low-temperature and high-field phase the broad NMR lineshapes suggest ordered
local moments, rather than a long wavelength quasiparticle spin density
modulation expected for an FFLO phase.Comment: 4 pages, 4 figures. to appear in Phys. Rev. Let
Spin relaxation in quantum dots due to electron exchange with leads
We calculate spin relaxation rates in lateral quantum dot systems due to
electron exchange between dots and leads. Using rate equations, we develop a
theoretical description of the experimentally observed electric current in the
spin blockade regime of double quantum dots. Single expression fits the entire
current profile and describes the structure of both the conduction peaks and of
the suppressed (`valley') region. Extrinsic rates calculated here have to be
taken into account for accurate extraction of intrinsic relaxation rates due to
the spin-orbit and hyperfine spin scattering mechanisms from spin blockade
measurements.Comment: 4+ pages, 3 figures, submitted to PR
Supercomputer Simulations of Disk Galaxies
The time evolution of models for an isolated disk of highly flattened
galaxies of stars is investigated by direct integration of the Newtonian
equations of motion of N=30,000 identical stars over a time span of many
galactic rotations. Certain astronomical implications of the simulations to
actual disk-shaped (i.e. rapidly rotating) galaxies are explored as well.Comment: 3 pages, 2 figure Aat.sty, Aattable.sty, presented by E. Griv at the
JENAM 2000, S02, Moscow, Russia, 200
Nodal gap structure of BaFe_2(As_{1-x}P_x)_2 from angle-resolved thermal conductivity in a magnetic field
The structure of the superconducting order parameter in the iron-pnictide
superconductor BaFe(AsP) (\,K) with line
nodes is studied by the angle-resolved thermal conductivity measurements in a
magnetic field rotated within the basal plane. We find that the thermal
conductivity displays distinct fourfold oscillations with minima when the field
is directed at with respect to the tetragonal a-axis. We discuss
possible gap structures that can account for the data, and conclude that the
observed results are most consistent with the closed nodal loops located at the
flat parts of the electron Fermi surface with high Fermi velocity.Comment: 4 pages, 4 figure
Створення та редагування аніміції за допомогою графічного редактора
We demonstrate the use of tools to influence the form of animation curves to change the direction of motion of the object, its speed, acceleration, moment of transition in a particular situation. These operations are performed by editing keys, editing tangents (or tangential) and directly through functional curves.Продемонстрировано применение инструментов влияния на форму анимационных кривых с целью изменения направления движения объекта, его скорости, ускорения, момента перехода в то или иное положение. Эти операции выполнены с помощью редактирования ключей, редактирования тангенсов (или касательных) и непосредственно через функциональные кривые.Продемонстровано застосування інструментів впливу на формуанімаційних кривих з метою зміни напрямку руху об’єкта, його швидкості, прискорення, моменту переходу в те чи інше становище. Ці операції виконані за допомогою редагування ключів, редагування тангенсів (або дотичних) та безпосередньо через функціональні криві
Alien Species in the Flora of the Middle Volga Region
The article presents information on the diversity and structure of the alien flora of the Middle Volga region on the border between the steppe and forest-steppe zones of the European botanical and geographical province. In the studied area, we identified 440 alien species of plants (24.6% of the total floristic diversity), including 59 invasive and potentially invasive species, the dispersal of which has already caused environmental consequences or could become a threat in the future. According to the degree of naturalization, alien plant species among the regional flora are represented by 146 ephemerophytes (33.2%), 122 colonophytes (27.7%), 151 epecophytes (34.3%) and 21 agriophytes (4.8%). As verified via the main method of skidding, alien species are distributed almost equally – 228 xenophytes (51.8%) and 212 ergasiophygophytes (48.2%). It was revealed that of the 150 species of alien plants, there are only 84 of the most common European species in the Middle Volga region, most of which do not show high cenotic activity. The obtained results actualize the development of a system of ecological and economic assessment of the consequences of introducing alien plant species into regional flora.
Keywords: alien plants, invasive species, Middle Volga region, regional flor
Uncertainty relations in curved spaces
Uncertainty relations for particle motion in curved spaces are discussed. The
relations are shown to be topologically invariant. New coordinate system on a
sphere appropriate to the problem is proposed. The case of a sphere is
considered in details. The investigation can be of interest for string and
brane theory, solid state physics (quantum wires) and quantum optics.Comment: published version; phase space structure discussion adde
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