4,565 research outputs found
Spin transport in proximity induced ferromagnetic graphene
Magnetic gates in close proximity to graphene can induce ferromagnetic
correlations. We study the effect of such induced magnetization dependent
Zeeman splittings on the graphene transport properties. We estimate that
induced spin splittings of the order of \Delta ~ 5 meV could be achieved with
the use of magnetic insulator gates, e.g. EuO-gates, deposited on top of
graphene. We demonstrate that such splittings in proximity induced
ferromagnetic graphene could be determined directly from the tunneling
resonances in the linear response conductance, as the top gate creates also a
tunable barrier in the graphene layer. We show how such splittings could also
be determined independently by magnetoresistance measurements in a spin-valve
geometry. Because the spin polarization of the current near the Dirac point
increases with the length of the barrier, long magnetic gates are desirable for
determining \Delta experimentally.Comment: 9 pages, 11 figure
Revisiting the Hubble sequence in the SDSS DR7 spectroscopic sample: a publicly available bayesian automated classification
We present an automated morphological classification in 4 types
(E,S0,Sab,Scd) of ~700.000 galaxies from the SDSS DR7 spectroscopic sample
based on support vector machines. The main new property of the classification
is that we associate to each galaxy a probability of being in the four
morphological classes instead of assigning a single class. The classification
is therefore better adapted to nature where we expect a continuos transition
between different morphological types. The algorithm is trained with a visual
classification and then compared to several independent visual classifications
including the Galaxy Zoo first release catalog. We find a very good correlation
between the automated classification and classical visual ones. The compiled
catalog is intended for use in different applications and can be downloaded at
http://gepicom04.obspm.fr/sdss_morphology/Morphology_2010.html and soon from
the CasJobs database.Comment: A&A in press, english corrections from language editor adde
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