12,639 research outputs found

    Polyhedral vesicles

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    Polyhedral vesicles with a large bending modulus of the membrane such as the gel phase lipid membrane were studied using a Brownian dynamics simulation. The vesicles exhibit various polyhedral morphologies such as tetrahedron and cube shapes. We clarified two types of line defects on the edges of the polyhedrons: cracks of both monolayers at the spontaneous curvature of monolayer C0<0C_{\text {0}}<0, and a crack of the inner monolayer at C00C_{\text {0}}\ge0. Around the latter defect, the inner monolayer curves positively. Our results suggested that the polyhedral morphology is controlled by C0C_{\text {0}}.Comment: 4 pages, 5 figure

    Numerical approach for retention characteristics of double floating-gate memories

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    We report on a numerical investigation in which memory characteristics of double floating-gate (DFG) structure were compared to those of the conventional single floating-gate structure, including an interference effect between two cells. We found that the advantage of the DFG structure is its longer retention time and the disadvantage is its smaller threshold voltage shift. We also provide an analytical form of charging energy including the interference effect.Comment: 4 pages, 4 figure

    All-optical transport and compression of ytterbium atoms into the surface of a solid immersion lens

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    We present an all-optical method to load 174Yb atoms into a single layer of an optical trap near the surface of a solid immersion lens which improves the numerical aperture of a microscope system. Atoms are transported to a region 20 um below the surface using a system comprised by three optical dipole traps. The "optical accordion" technique is used to create a condensate and compress the atoms to a width of 120 nm and a distance of 1.8 um away from the surface. Moreover, we are able to verify that after compression the condensate behaves as a two-dimensional quantum gas.Comment: 5 pages, 5 figure

    Electro-mechano-optical detection of nuclear magnetic resonance

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    Signal reception of nuclear magnetic resonance (NMR) usually relies on electrical amplification of the electromotive force caused by nuclear induction. Here, we report up-conversion of a radio-frequency NMR signal to an optical regime using a high-stress silicon nitride membrane that interfaces the electrical detection circuit and an optical cavity through the electro-mechanical and the opto-mechanical couplings. This enables optical NMR detection without sacrificing the versatility of the traditional nuclear induction approach. While the signal-to-noise ratio is currently limited by the Brownian motion of the membrane as well as additional technical noise, we find it can exceed that of the conventional electrical schemes by increasing the electro-mechanical coupling strength. The electro-mechano-optical NMR detection presented here opens the possibility of mechanical parametric amplification of NMR signals. Moreover, it can potentially be combined with the laser cooling technique applied to nuclear spins.Comment: 20 pages, 10 figure
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