36 research outputs found
Quantum Interference between Impurities: Creating Novel Many-Body States in s-wave Superconductors
We demonstrate that quantum interference of electronic waves that are
scattered by multiple magnetic impurities in an s-wave superconductor gives
rise to novel bound states. We predict that by varying the inter-impurity
distance or the relative angle between the impurity spins, the states' quantum
numbers, as well as their distinct frequency and spatial dependencies, can be
altered. Finally, we show that the superconductor can be driven through
multiple local crossovers in which its spin polarization, , changes
between and 1.Comment: 4 pages, 4 figure
Analytical solutions to zeroth-order dispersion relations of a cylindrical metallic nanowire
Zeroth-order complex dispersion relations of a cylindrical metallic nanowire
have been solved out analytically with approximate methods. The analytical
solutions are valid for the sections of the dispersion relations whose
frequencies are close to the Surface Plasmon frequency. The back bending of the
Surface Plasmon-Polaritons(SPPs) can be well described by the analytical
solutions, confirming that the back bending is originated from the metal Ohmic
loss. The utility of the back bending point in the dispersion relation for the
measurement of the metallic Ohimc loss has also been suggested.Comment: 6pages, 3figure
Genetic Interaction between MTMR2 and FIG4 Phospholipid Phosphatases Involved in Charcot-Marie-Tooth Neuropathies
We previously reported that autosomal recessive demyelinating Charcot-Marie-Tooth (CMT) type 4B1 neuropathy with myelin outfoldings is caused by loss of MTMR2 (Myotubularin-related 2) in humans, and we created a faithful mouse model of the disease. MTMR2 dephosphorylates both PtdIns3P and PtdIns(3,5)P2, thereby regulating membrane trafficking. However, the function of MTMR2 and the role of the MTMR2 phospholipid phosphatase activity in vivo in the nerve still remain to be assessed. Mutations in FIG4 are associated with CMT4J neuropathy characterized by both axonal and myelin damage in peripheral nerve. Loss of Fig4 function in the plt (pale tremor) mouse produces spongiform degeneration of the brain and peripheral neuropathy. Since FIG4 has a role in generation of PtdIns(3,5)P2 and MTMR2 catalyzes its dephosphorylation, these two phosphatases might be expected to have opposite effects in the control of PtdIns(3,5)P2 homeostasis and their mutations might have compensatory effects in vivo. To explore the role of the MTMR2 phospholipid phosphatase activity in vivo, we generated and characterized the Mtmr2/Fig4 double null mutant mice. Here we provide strong evidence that Mtmr2 and Fig4 functionally interact in both Schwann cells and neurons, and we reveal for the first time a role of Mtmr2 in neurons in vivo. Our results also suggest that imbalance of PtdIns(3,5)P2 is at the basis of altered longitudinal myelin growth and of myelin outfolding formation. Reduction of Fig4 by null heterozygosity and downregulation of PIKfyve both rescue Mtmr2-null myelin outfoldings in vivo and in vitro
Vps34 PI 3-kinase inactivation enhances insulin sensitivity through reprogramming of mitochondrial metabolism
Postdoctoral fellowships were from EU Marie Curie (PIEF-GA-2009–252916) and
EMBO (ALTF 753–2010) for SA and EU Marie Curie (PIIF-GA-2009–252846) for C.C. J.
M.H. was a recipient of a doctoral fellowship from Eisai UK Ltd. Work in our laboratories
was supported as follows: BV: MRC [G0700755], BBSRC (BB/I007806/1 and BB/
M013278/1), CRUK (C23338/A15965), the Ludwig Institute for Cancer Research and the
National Institute for Health Research (NIHR) UCL Hospitals Biomedical Research
Centre; J.M.B.: NIH AG039632, GM112524. and the Albert Einstein Diabetes Research
and Training Center Animal Physiology Core DK020541; E.G.: Barry Reed Cancer
Research fund; G.S.: BBSRC (BB/L020874/1) and B.H.F.; S.S.: Anatomical Society of
Great Britain (GT) and a Wellcome Trust Career Development Fellowship 074246/Z04/Z
(S.S.); R.K.S.: Wellcome Trust (WT098498) and M.R.C. (MRC_MC_UU_12012/5); S.A.
T. and L.C.: the Francis Crick Institute, which receives its core funding from CRUK
(FC001187), MRC (FC001187), and the Wellcome Trust (FC001187); Y.-L.C.: the CRUK
Cancer Imaging Centre in association with the MRC and DoH (England) grant C1060/
A10334, C1060/A16464, NHS funding to the NIHR BRC; B.P.: Inserm and the Fondation
pour la recherche médicale
Imaging surface photonic states with a circularly polarized tip
Photon unoccupied states tailored by nanostructures present at
sample surfaces can be probed using a scanning near-field optical
microscope including large detection angles (Chicanne C
Infrared near-field study of a localised absorption in a thin film
We study the conditions to perform micro-spectroscopy with a sub-wavelength lateral
resolution in the wavelength spectral range from 3 to 20 ÎĽm, taking advantage of the infrared
spectral signature of different chemical species. We utilised CLIO, a free electron laser, as the
photon source. The transmitted photons were collected by either fluoride or chalcogenide
glass fibres. Fibre tips were obtained through chemical etching by organic solvents.
Metallisation of the tips permits to achieve lateral resolution of the order of the tip size.
However, parasitic propagation of the light in the film reduces the contrast between irradiated
and non-irradiated zones. We exemplify our set up with near-field infrared spectra obtained for
polymer thin films deposited onto silicon wafers