Josephson radiation from gapless andreev bound states in HgTe-based topological junctions

Review (2017)
Author(s)

R. S. Deacon (RIKEN Center for Emergent Matter Science (CEMS))

J Wiedenmann (Julius-Maximilians-Universität Würzburg)

E Bocquillon (Julius-Maximilians-Universität Würzburg)

F. Domínguez (Julius-Maximilians-Universität Würzburg)

T. M. Klapwijk (TU Delft - QN/Klapwijk Lab, Kavli institute of nanoscience Delft)

P. Leubner (Julius-Maximilians-Universität Würzburg)

C Brüne (Julius-Maximilians-Universität Würzburg)

E. M. Hankiewicz (Julius-Maximilians-Universität Würzburg)

S. Tarucha (University of Tokyo, RIKEN Center for Emergent Matter Science (CEMS))

K Ishibashi (RIKEN Center for Emergent Matter Science (CEMS))

H Buhmann (Julius-Maximilians-Universität Würzburg)

Laurens W. Molenkamp (Julius-Maximilians-Universität Würzburg)

Research Group
QN/Klapwijk Lab
DOI related publication
https://doi.org/10.1103/PhysRevX.7.021011
More Info
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Publication Year
2017
Language
English
Research Group
QN/Klapwijk Lab
Issue number
2
Volume number
7
Article number
021011
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Abstract

Frequency analysis of the rf emission of oscillating Josephson supercurrent is a powerful passive way of probing properties of topological Josephson junctions. In particular, measurements of the Josephson emission enable the detection of topological gapless Andreev bound states that give rise to emission at half the Josephson frequency fj rather than conventional emission at fj. Here, we report direct measurement of rf emission spectra on Josephson junctions made of HgTe-based gate-tunable topological weak links. The emission spectra exhibit a clear signal at half the Josephson frequency fj=2. The linewidths of emission lines indicate a coherence time of 0.3-4 ns for the fj=2 line, much shorter than for the fj line (3-4 ns). These observations strongly point towards the presence of topological gapless Andreev bound states and pave the way for a future HgTe-based platform for topological quantum computation.