120 research outputs found

    Topologically protected charge transfer along the edge of a chiral p\textit{p}-wave superconductor

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    The Majorana fermions propagating along the edge of a topological superconductor with px+ipyp_x+ip_y pairing deliver a shot noise power of 12×e2/h\frac{1}{2}\times e^2/h per eV of voltage bias. We calculate the full counting statistics of the transferred charge and find that it becomes trinomial in the low-temperature limit, distinct from the binomial statistics of charge-ee transfer in a single-mode nanowire or charge-2e2e transfer through a normal-superconductor interface. All even-order correlators of current fluctuations have a universal quantized value, insensitive to disorder and decoherence. These electrical signatures are experimentally accessible, because they persist for temperatures and voltages large compared to the Thouless energy.Comment: 5 pages, 4 figures. v3 [post-publication]: added an appendix on the effect of a tunnel barrier at the normal-superconductor contac

    Acceleration of diffusion in ethylammonium nitrate ionic liquid confined between parallel glass plates

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    The bulk self diffusion of the ethylammonium cation and the nitrate anion can both be described by respective single diffusion coefficients. Diffusion of the anion is 1.7 times higher than that of the cation. This indicates no tight association of the ions in the ionic liquid. For the ethylammonium cation confined between glass plates the effective diffusion coefficient along, as well as normal to the confining glass plates is higher by a factor of 1.86 as compared to that in the bulk. The same time, NMR T2 relaxation of protons of NH3 group of the EA cation is faster by a factor of 22 than that in bulk. 2H NMR spectra of selectively labeled CH2 and CH3 groups of EA do not demonstrate any ordering of the EA between the glass plates. We suggested that these data favor a model where a bulk isotropic sponge like structure of EAN is saved in the confinement, but sizes of connecting channels increases. Those leads to faster translational diffusion and faster exchange processes of protons of NH3 group, in comparison with the bulk.Comment: 11 pages, 5 figures, 1 tabl

    Ultrafast dynamics of cold Fermi gas after a local quench

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    We consider non-equilibrium dynamics of two initially independent reservoirs AA and BB filled with a cold Fermi gas coupled and decoupled by two quantum quenches following one another. We find that the von Neumann entropy production induced by the quench is faster than thermal transport between the reservoirs and defines the short-time dynamics of the system. We analyze the energy change in the system which adds up the heat transferred between AA and BB and the work done by the quench to uncouple the reservoirs. In the case when AA and BB interact for a short time, we notice an energy increase in both reservoirs upon decoupling. This energy gain results from the quench's work and does not depend on the initial temperature imbalance between the reservoirs. We relate the quench's work to the mutual correlations of AA and BB expressed through their von Neumann entropies. Utilizing this relation, we show that once AA and BB become coupled, their entropies grow (on a timescale of the Fermi time) faster than the heat flow within the system. This result may provide a track of quantum correlations' generation at finite temperatures which one may probe in ultracold atoms, where we expect the characteristic timescale of correlations' growth to be ∼0.1ms\sim 0.1 {\rm ms}.Comment: 12 pages, 6 figures (published version

    Subunit Mobility and the Chaperone Activity of Recombinant αB-Crystallin

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    The comparison of the chaperone-like activity of native and covalently cross-linked human αB-crystallins has confirmed the important role of the subunit mobility in the chaperoning mechanism. Our data clearly demonstrate that the chaperone-like activity of α-crystallin is not only a surface phenomenon as was suggested by some researchers

    Synthesis, crystal structure and hydrolysis of novel isomeric cage (P-C/P-O)-phosphoranes on the basis of 4,4,5,5-tetramethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane and hexafluoroacetone

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    © The Royal Society of Chemistry 2016.The reaction of 4,4,5,5-tetramethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane with hexafluoroacetone leads to the simultaneous formation of regioisomeric cage (P-C/P-O)-phosphoranes, the structures of which are unequivocally confirmed by XRD. The rearrangement of the P-C-isomer to P-O-isomer with high stereoselectivity (>96%) takes place in methylene chloride solution with the retention of the phosphorus coordination. It was found that the stepwise hydrolysis of the P-O-isomer initially gives 2-(2,3-dihydroxy-1,2-diphenyl-3-trifluoromethyl-4,4,4-trifluorobutyloxy)-4,4,5,5-tetramethyl-2-oxo-1,3,2-dioxaphospholane as the only stereoisomer whose structure is also confirmed by XRD. Further hydrolysis of this compound leads to the formation of 2,3-dihydroxy-3-trifluoromethyl-4,4,4-trifluoro-1,2-diphenylbutylphosphate and pinacol, which forms the solvate in the crystal. Hydrolysis of the P-C-isomer yields 2-hydroxy-4,4,5,5-tetramethyl-2-oxo-1,3,2-dioxaphospholane, benzoin and hexafluoroisopropanol
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