Thin amorphous molybdenum silicide superconducting shells around individual nanowires deposited via magnetron co-sputtering

Abstract

Employing amorphous superconductors, such as Type-II molybdenum silicide (MoSi), instead of crystalline materials significantly simplifies the material deposition and scalable nanoscale prototyping, beneficial for quantum electronic and photonic device fabrication. In this work, deposition of amorphous superconductive MoSi thin films on flat and nanowire (NW) substrates was demonstrated via pulsed direct-current magnetron co-sputtering from molybdenum and silicon targets in an argon atmosphere. MoSi films were deposited on oxidized silicon wafers and Ga2O3 NWs with 6 nm Al2O3 insulating shell, grown around the NWs using atomic layer deposition, and studied using scanning and transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Four-point Cr/Au electrical contacts were defined on the thin films and on individual Ga2O3-Al2O3-MoSi core-shell NWs using lithography for low-temperature electrical measurements. By controlling the sputtering power of the targets and thus adjusting the molybdenum-to-silicon ratio in the MoSi films, their properties were optimized to achieve critical temperature Tc of 7.25 K. Such superconducting shell NWs could provide new avenues for fundamental studies and interfacing with other materials for quantum device applications.

References in corpus (19)

• Epitaxy of Semiconductor-Superconductor nanowires
• Superconducting materials: Challenges and opportunities for large-scale applications
• Flux-induced Majorana modes in full-shell nanowires
• Flux-induced topological superconductivity in full-shell nanowires
• Topological superconductivity in full shell proximitized nanowires
• Upper critical field, Hall effect and magnetoresistance in the iron-based layered superconductor LaFeAsO_{0.9}F_{0.1-δ}
• Hall effect and magnetoresistance in the normal state of the superconductor LaO${}_{0.9}$F${}_{0.1-x}$FeAs
• Superconducting nanowire for single-photon detection: progress, challenges and opportunities
• Nontopological zero-bias peaks in full-shell nanowires induced by flux tunable Andreev states
• A superconducting-nanowire single-photon camera with 400,000 pixels
• Nanomaterials for Quantum Information Science and Engineering
• Resistance in Superconductors
• Quantum meets classical phase transition: Low-temperature anomaly in disordered superconductors near $B_{c2}$
• Asymmetric Little-Parks Oscillations in Full Shell Double Nanowires
• Physical properties of amorphous molybdenum silicide films for single photon detectors
• Superconducting MoSi nanowires
• Superconducting insulators and localization of Cooper pairs
• The role of Al2O3 interlayer in the synthesis of ZnS/Al2O3/MoS2 core-shell nanowires
• MoSe2 and WSe2 shell morphology control via temperature optimization during two-step growth of ZnSe-based core-shell nanowires