2019/06/04 by Matthieu C. Dartiailh, William Mayer, Joseph Yuan +4 · 1 voice · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.126.036802
published as Phys. Rev. Lett. 126, 036802 (2021)
arxiv published 2019/06/04 · arxiv created 2021/01/22 · arxiv updated 2021/01/25
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 π-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.