3,377 research outputs found
Entanglement Cost of Three-Level Antisymmetric States
We show that the entanglement cost of the three-dimensional antisymmetric
states is one ebit.Comment: 8page
Projection neurons in lamina III of the rat spinal cord are selectively innervated by local dynorphin-containing excitatory neurons
Large projection neurons in lamina III of the rat spinal cord that express the neurokinin 1 receptor are densely innervated by peptidergic primary afferent nociceptors and more sparsely by low-threshold myelinated afferents. However, we know little about their input from other glutamatergic neurons. Here we show that these cells receive numerous contacts from nonprimary boutons that express the vesicular glutamate transporter 2 (VGLUT2), and form asymmetrical synapses on their dendrites and cell bodies. These synapses are significantly smaller than those formed by peptidergic afferents, but provide a substantial proportion of the glutamatergic synapses that the cells receive (over a third of those in laminae I–II and half of those in deeper laminae). Surprisingly, although the dynorphin precursor preprodynorphin (PPD) was only present in 4–7% of VGLUT2 boutons in laminae I–IV, it was found in 58% of the VGLUT2 boutons that contacted these cells. This indicates a highly selective targeting of the lamina III projection cells by glutamatergic neurons that express PPD, and these are likely to correspond to local neurons (interneurons and possibly projection cells). Since many PPD-expressing dorsal horn neurons respond to noxious stimulation, this suggests that the lamina III projection cells receive powerful monosynaptic and polysynaptic nociceptive input. Excitatory interneurons in the dorsal horn have been shown to possess IA currents, which limit their excitability and can underlie a form of activity-dependent intrinsic plasticity. It is therefore likely that polysynaptic inputs to the lamina III projection neurons are recruited during the development of chronic pain states
Dust properties in the cold and hot gas phases of the ATLAS3D early-type galaxies as revealed by AKARI
The properties of the dust in the cold and hot gas phases of early-type
galaxies (ETGs) are key to understand ETG evolution. We thus conducted a
systematic study of the dust in a large sample of local ETGs, focusing on
relations between the dust and the molecular, atomic, and X-ray gas of the
galaxies, as well as their environment. We estimated the dust temperatures and
masses of the 260 ETGs from the ATLAS3D survey, using fits to their spectral
energy distributions primarily constructed from AKARI measurements. We also
used literature measurements of the cold (CO and HI) and X-ray gas phases. Our
ETGs show no correlation between their dust and stellar masses, suggesting
inefficient dust production by stars and/or dust destruction in X-ray gas. The
global dust-to-gas mass ratios of ETGs are generally lower than those of
late-type galaxies, likely due to dust-poor HI envelopes in ETGs. They are also
higher in Virgo Cluster ETGs than in group and field ETGs, but the same ratios
measured in the central parts of the galaxies only are independent of galaxy
environment. Slow-rotating ETGs have systematically lower dust masses than
fast-rotating ETGs. The dust masses and X-ray luminosities are correlated in
fast-rotating ETGs, whose star formation rates are also correlated with the
X-ray luminosities. The correlation between dust and X-rays in fast-rotating
ETGs appears to be caused by residual star formation, while slow-rotating ETGs
are likely well evolved, and thus exhausting their dust. These results appear
consistent with the postulated evolution of ETGs, whereby fast-rotating ETGs
form by mergers of late-type galaxies and associated bulge growth, while
slow-rotating ETGs form by (dry) mergers of fast-rotating ETGs. Central cold
dense gas appears to be resilient against ram pressure stripping, suggesting
that Virgo Cluster ETGs may not suffer strong related star formation
suppression.Comment: 18 pages, 7 figures, accepted for publication in A&
Incoherent Noise and Quantum Information Processing
Incoherence in the controlled Hamiltonian is an important limitation on the
precision of coherent control in quantum information processing. Incoherence
can typically be modelled as a distribution of unitary processes arising from
slowly varying experimental parameters. We show how it introduces artifacts in
quantum process tomography and we explain how the resulting estimate of the
superoperator may not be completely positive. We then go on to attack the
inverse problem of extracting an effective distribution of unitaries that
characterizes the incoherence via a perturbation theory analysis of the
superoperator eigenvalue spectra.Comment: 15 pages, 5 figures, replaced with future JCP published versio
Spin wave dispersion softening in the ferromagnetic Kondo lattice model for manganites
Spin dynamics is calculated in the ferromagnetic (FM) state of the
generalized Kondo lattice model taking into account strong on-site correlations
between e_g electrons and antiferromagnetic (AFM) exchange among t_{2g} spins.
Our study suggests that competing FM double-exchange and AFM super-exchange
interaction lead to a rather nontrivial spin-wave spectrum. While spin
excitations have a conventional Dq^2 spectrum in the long-wavelength limit,
there is a strong deviation from the spin-wave spectrum of the isotropic
Heisenberg model close to the zone boundary. The relevance of our results to
the experimental data are discussed.Comment: 6 RevTex pages, 3 embedded PostScript figure
Continuous phase transition and negative specific heat in finite nuclei
The liquid-gas phase transition in finite nuclei is studied in a heated
liquid-drop model where the nuclear drop is assumed to be in thermodynamic
equilibrium with its own evaporated nucleonic vapor conserving the total baryon
number and isospin of the system. It is found that in the liquid-vapor
coexistence region the pressure is not a constant on an isotherm indicating
that the transition is continuous. At constant pressure, the caloric curve
shows some anomalies, namely, the systems studied exhibit negative heat
capacity in a small temperature domain. The dependence of this specific feature
on the mass and isospin of the nucleus, Coulomb interaction and the chosen
pressure is studied. The effects of the presence of clusters in the vapor phase
on specific heat have also been explored.Comment: 18 pages, 13 figures; Phys. Rev. C (in press
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