@article{WiedenmannBocquillonDeaconetal.2016,
  author    = {Wiedenmann, J. and Bocquillon, E. and Deacon, R.S. and Hartinger, S. and Herrmann, O. and Klapwijk, T.M. and Maier, L. and Ames, C. and Br{\"u}ne, C. and Gould, C. and Oiwa, A. and Ishibashi, K. and Tarucha, S. and Buhmann, H. and Molenkamp, L.W.},
  title     = {4π-periodic Josephson supercurrent in HgTe-based topological Josephson junctions},
  series = {Nature Communications},
  volume    = {7},
  journal   = {Nature Communications},
  doi       = {10.1038/ncomms10303},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175353},
  year      = {2016},
  abstract  = {The Josephson effect describes the generic appearance of a supercurrent in a weak link between two superconductors. Its exact physical nature deeply influences the properties of the supercurrent. In recent years, considerable efforts have focused on the coupling of superconductors to the surface states of a three-dimensional topological insulator. In such a material, an unconventional induced p-wave superconductivity should occur, with a doublet of topologically protected gapless Andreev bound states, whose energies vary 4π-periodically with the superconducting phase difference across the junction. In this article, we report the observation of an anomalous response to rf irradiation in a Josephson junction made of a HgTe weak link. The response is understood as due to a 4π-periodic contribution to the supercurrent, and its amplitude is compatible with the expected contribution of a gapless Andreev doublet. Our work opens the way to more elaborate experiments to investigate the induced superconductivity in a three-dimensional insulator.},
  language  = {en}
}
@article{DeaconWiedenmannBocquillonetal.2017,
  author    = {Deacon, R. S. and Wiedenmann, J. and Bocquillon, E. and Dom{\´i}nguez, F. and Klapwijk, T. M. and Leubner, P. and Br{\"u}ne, C. and Hankiewicz, E. M. and Tarucha, S. and Ishibashi, K. and Buhmann, H. and Molenkamp, L. W.},
  title     = {Josephson Radiation from Gapless Andreev Bound States in HgTe-Based Topological Junctions},
  series = {Physical Review X},
  volume    = {7},
  journal   = {Physical Review X},
  number    = {021011},
  doi       = {10.1103/PhysRevX.7.021011},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170969},
  year      = {2017},
  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 f\(_{J}\) rather than conventional emission at f\(_{J}\). 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 f\(_{J}\)/2. The linewidths of emission lines indicate a coherence time of 0.3-4 ns for the f\(_{J}\)/2 line, much shorter than for the f\(_{J}\) 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.},
  language  = {en}
}