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Ultrathin niobium nanofilms on fiber optical tapers--a new route towards low-loss hybrid plasmonic modes.

Due to the ongoing improvement in nanostructuring technology, ultrathin metallic nanofilms have recently gained substantial attention in plasmonics, e.g. as building blocks of metasurfaces. Typically, noble metals such as silver or gold are the materials of choice, due to their excellent optical properties, however they also possess some intrinsic disadvantages. Here, we introduce niobium nanofilms (~10 nm thickness) as an alternate plasmonic platform. We demonstrate functionality by depositing a niobium nanofilm on a plasmonic fiber taper, and observe a dielectric-loaded niobium surface-plasmon excitation for the first time, with a modal attenuation of only 3–4 dB/mm in aqueous environment and a refractive index sensitivity up to 15 μm/RIU if the analyte index exceeds 1.42. We show that the niobium nanofilm possesses bulk optical properties, is continuous, homogenous, and inert against any environmental influence, thus possessing several superior properties compared to noble metal nanofilms. These results demonstrate that ultrathin niobium nanofilms can serve as a new platform for biomedical diagnostics, superconducting photonics, ultrathin metasurfaces or new types of optoelectronic devices.

Investigation of all niobium nano-SQUIDs based on sub-micrometer cross-type Josephson junctions

We report on the development of highly sensitive SQUIDs featuring sub-micrometer loop dimensions. The integration of high quality and low capacitance SIS Nb/AlOx/Nb cross-type Josephson tunnel junctions results in white flux noise levels as low as 66 n

Noise characterization of highly sensitive SQUID magnetometer systems in unshielded environments

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A LTS-SQUID System for Archaeological Prospection and Its Practical Test in Peru

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Recent Developments in Superconductor Digital Electronics Technology at FLUXONICS Foundry

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Quantum Detection Meets Archaeology – Magnetic Prospection with SQUIDs, Highly Sensitive and Fast

, well below state-of-the-art values of their Nb-based counterparts based on constriction type junctions. Estimation of the spin sensitivity of the best SQUIDs yield

Nearly quantum limited nanoSQUIDs based on cross-type Nb/AlO x /Nb junctions

S_\mu^{ 1/2} < 7 \mu_B

Charlemagne's Summit Canal: An Early Medieval Hydro-Engineering Project for Passing the Central European Watershed

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Localisation of buried ferromagnetic objects based on minimum‐norm‐estimations: A simulation study

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Realization of a classical counterpart of a scalable design for adiabatic quantum computation

in the white noise region, suitable for the investigation of small spin systems. We discuss fabrication challenges, show results on the electrical characterization of devices with various pickup loops, and describe options for further improvement, which may push the sensitivity of such devices even to single spin resolution.