Reflectionless tunneling in planar Nb/GaAs hybrid junctions

Abstract

Reflectionless-tunneling was observed in Nb/GaAs superconductor/semiconductor junctions fabricated through a two-step procedure. First, periodic $\delta$-doped layers were grown by molecular beam epitaxy near the GaAs surface, followed by an As cap layer to protect the surface during {\it ex-situ} transfer. Second, Nb was deposited by dc-magnetron sputtering onto the GaAs(001) 2 $\times$ 4 surface {\it in-situ} after thermal desorption of the cap layer. The magnetotransport behavior of the resulting hybrid junctions was successfully analyzed within the random matrix theory of phase-coherent Andreev transport. The impact of junction morphology on reflectionless tunneling and the applicability of the fabrication technique to the realization of complex superconductor/semiconductor mesoscopic systems are discussed.

10 pages, 3 figures, to be published in Appl. Phys. Lett

Cited by in corpus (8)

• Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
• Doubled Full Shot Noise in Quantum Coherent Superconductor - Semiconductor Junctions
• Multiple Andreev reflections in a quantum dot coupled to superconductors: Effects of spin-orbit coupling
• Mesoscopic proximity effect in double barrier Superconductor/Normal Metal junctions
• Evidence for a New Excitation at the Interface Between a High-Tc Superconductor and a Topological Insulator
• Coherent transport in Nb/delta-doped-GaAs hybrid microstructures
• Extremely weak sub-kelvin electron-phonon coupling in InAs On Insulator
• Transport across meso-junctions of highly doped Si with different superconductors