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arXiv · 1906.01179

Phase signature of topological transition in Josephson Junctions

Matthieu C. Dartiailh·William Mayer·Joseph Yuan·Kaushini S. Wickramasinghe·Alex Matos-Abiague·Igor Žutić·Javad Shabani
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Abstract

Topological superconductivity holds promise for fault-tolerant quantum computing. While planar Josephson junctions are attractive candidates to realize this exotic state, direct phase-measurements as the fingerprint of the topological transition are missing. By embedding two gate-tunable Al/InAs Josephson junctions in a loop geometry, we measure a $\pi$-jump in the junction phase with increasing in-plane magnetic field, ${\bf B}_\|$. This jump is accompanied by a minimum of the critical current, indicating a closing and reopening of the superconducting gap, strongly anisotropic in ${\bf B}_\|$. Our theory confirms that these signatures of a topological transition are compatible with the emergence of Majorana states.

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Matthieu C. Dartiailh, William Mayer, Joseph Yuan, Kaushini S. Wickramasinghe, Alex Matos-Abiague, Igor Žutić, Javad Shabani. 2019-06-04. Phase signature of topological transition in Josephson Junctions. https://doi.org/10.1103/physrevlett.126.036802

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