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تسجيل مستخدم جديدSuperconducting networks with the proximity effect
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We report on the first observation of a novel type of superconducting proximity network using a superconductor-normal metal bilayer. Little-Parks oscillation measurements show that the superconducting current flows through a path enclosed by the edge rather than by the center of the Pb/Au wire in the network. Furthermore, several peaks were observed in a power spectrum analysis. We observed that the sequence of these peaks and that of the monolayer network were connected by the power function, which is a factor of the line width, S_{B_n} = alpha^{n-2}S_{A_n}. This suggests that even in a proximity network vortices are arranged in a way identical to a monolayer network.
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A proximity-effect thermometer measures the temperature dependent critical supercurrent in a long superconductor - normal metal - superconductor (SNS) Josephson junction. Typically, the transition from the superconducting to the normal state is detec
ted by monitoring the appearance of a voltage across the junction. We describe a new approach to detect the transition based on the temperature increase in the resistive state due to Joule heating. Our method increases the sensitivity and is especially applicable for temperatures below about 300 mK.
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zero-bias conductance peak with a tiny peak width of $sim$ 6 $mu$V. The central peak of the trident peak presents the dc-Josephson current, and the side peaks may reflect an induced unconventional Cooper pairing. Additionally, the critical currents followed inverse to temperature, which may also reflect the presence of an unconventional proximity effect. Furthermore, microwave irradiation derived a drastic change in the conductance spectra from the peak structure into oscillatory ones, a hallmark of the ac-Josephson supercurrent. The current-phase relation of the ac-Josephson effect under high power radiofrequency-irradiation was found to be 4$pi$-periodic. The results suggest that the junction based on magnetically doped 3D TIs may realize an unconventional Cooper pairing, thus enabling access to the basic physics of Majorana bound states and unconventional superconductivity.
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energy scales of ~1 meV have hindered the characterization of the emergent electronic phase, limiting it to extremely low temperatures. In this work, we use molecular beam epitaxy to grow topological insulator Bi$_{2}$Te$_{3}$ in a range of thicknesses on top of a high-T$_{c}$ superconductor Fe(Te,Se). Using scanning tunneling microscopy and spectroscopy, we detect {Delta}$_{ind}$ as high as ~3.5 meV, which is the largest reported gap induced by proximity to an s-wave superconductor to-date. We find that {Delta}$_{ind}$ decays with Bi$_{2}$Te$_{3}$ thickness, but remains finite even after the topological surface states had been formed. Finally, by imaging the scattering and interference of surface state electrons, we provide a microscopic visualization of the fully gaped Bi$_{2}$Te$_{3}$ surface state due to Cooper pairing. Our results establish Fe-based high-T$_{c}$ superconductors as a promising new platform for realizing high-T$_{c}$ topological superconductivity.
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