• Johnson, Erik
• Carrad, Damon James
• Nordqvist, Thomas Kanne
• Jespersen, Thomas Sand
• Nygård, Jesper
• Fiordaliso, Elisabetta M.
• Bjergfelt, Martin

Abstract

<p>We report in situ synthesis of crystalline indium islands on InAs nanowires grown by molecular beam epitaxy. Structural analysis by transmission electron microscopy showed that In crystals grew in a tetragonal body-centered crystal structure within two families of orientations relative to wurtzite InAs. The crystalline islands had lengths &lt; 500 nm and low-energy surfaces, suggesting that growth was driven mainly by surface energy minimization. Electrical transport through In/InAs devices exhibited Cooper pair charging, evidencing charge parity preservation and a pristine In/InAs interface, with an induced superconducting gap similar to 0.45 meV. Cooper pair charging persisted to temperatures &gt; 1.2 K and magnetic fields similar to 0.7 T, demonstrating that In/InAs hybrids belong to an expanding class of semiconductor/superconductor hybrids operating over a wider parameter space than state-of-the-art Al-based hybrids. Engineering crystal morphology while isolating single islands using shadow epitaxy provides an interesting alternative to previous semiconductor/superconductor hybrid morphologies and device geometries.</p>

Topics

• morphology
• surface
• semiconductor
• transmission electron microscopy
• surface energy
• Indium
• superconductivity
• superconductivity