68,434 research outputs found
Stray field and superconducting surface spin valve effect in LaCaMnO/YBaCuO bilayers
Electronic transport and magnetization measurements were performed on
LaCaMnO/YBaCuO (LCMO/YBCO) bilayers
below the superconducting transition temperature in order to study the
interaction between magnetism and superconductivity. This study shows that a
substantial number of weakly pinned vortices are induced in the YBCO layer by
the large out-of-plane stray field in the domain walls. Their motion gives rise
to large dissipation peaks at the coercive field. The angular dependent
magnetoresistance (MR) data reveal the interaction between the stripe domain
structure present in the LCMO layer and the vortices and anti-vortices induced
in the YBCO layer by the out-of-plane stray field. In addition, this study
shows that a superconducting surface spin valve effect is present in these
bilayers as a result of the relative orientation between the magnetization at
the LCMO/YBCO interface and the magnetization in the interior of the LCMO layer
that can be tuned by the rotation of a small . This latter finding will
facilitate the development of superconductive magnetoresistive memory devices.
These low-magnetic field MR data, furthermore, suggest that triplet
superconductivity is induced in the LCMO layer, which is consistent with recent
reports of triplet superconductivity in LCMO/YBCO/LCMO trilayers and LCMO/YBCO
bilayers.Comment: 14 pages, 3 figure
and cross sections
Inspired by the recent findings of the two states in the
mass spectrum at LHCb, we investigate the elastic and inelastic cross sections
of the , , and channels within the
constraints from heavy quark spin and flavour symmetry. The () bound states predicted in earlier
works should be accessible in elastic and/or inelastic processes of the and/or ( and/or ) interactions.Comment: Minor correction
Heavy quark spin symmetric molecular states from and other coupled channels in the light of the recent LHCb pentaquarks
We consider the states, together with and other coupled channels, and take an interaction consistent with heavy
quark spin symmetry, with the dynamical input obtained from an extension of the
local hidden gauge approach. By fitting only one parameter to the recent three
pentaquark states reported by the LHCb collaboration, we can reproduce the
three of them in base to the mass and the width, providing for them the quantum
numbers and approximate molecular structure as ,
, and , and isospin
. We find another state around 4374 MeV, of
structure, for which indications appear in the experimental spectrum. Two other
near degenerate states of and nature are also found around 4520 MeV, which although less clear,
are not incompatible with the observed spectrum. In addition, a state at the same energy appears, which however does not couple
to in wave, and hence it is not expected to show up in the LHCb
experiment.Comment: 8 page
- …