Evidence for p-wave pairing and hybridizing Majoranas in artificial finite-size Shiba chains
By Jens Wiebe
Department of Physics, Universität Hamburg, Germany
A magnetic chain on an s-wave superconductor hosting a spin spiral or strong spin-orbit coupling can potentially realize a one-dimensional topological superconductor with Majorana bound states on its edges.
Here, we investigate artificial spin chains which have been built atom-by-atom [1], with respect to the emergence of such topologically nontrivial electron phases.
We vary the substrate and adatom species and the interatomic distances in the chain [2-5].
By this approach we can adjust the energetic positions of the multi-orbital Yu-Shiba-Rusinov (YSR) states induced by the adatoms [2,3], the hybridizations between these YSR states [4], as well as the spin structure in the chain [5].
This eventually enables to tailor the multi-orbital YSR bands emerging in the chain such that a p-wave gap opens in one of the YSR bands [6], and weakly protected, interacting Majorana bound states [7] have been realized.
We acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via the Cluster of Excellence ’Advanced Imaging of Matter’ (EXC 2056-project ID 390715994), via the SFB-925 – project 170620586, and by the ERC via the Advanced Grant ADMIRE (No. 786020).
[1] D.-J. Choi, N. Lorente, J. Wiebe, K. von Bergmann, A. F. Otte, and A. J. Heinrich, Rev. Mod. Phys. 91, 041001 (2019).
[2] L. Schneider, M. Steinbrecher, L. Rózsa, J. Bouaziz, K. Palotás, M. dos Santos Dias, S. Lounis, J. Wiebe, and R. Wiesendanger, npj Quantum Materials 4, 42 (2019).
[3] L. Schneider, S. Brinker, M. Steinbrecher, J. Hermenau, T. Posske, M. dos Santos Dias, S. Lounis, R. Wiesendanger, and J. Wiebe, Nature Commun. 11, 4707 (2020).
[4] P. Beck, L. Schneider, L. Rózsa, K. Palotás, A. Lászlóffy, L. Szunyogh, J. Wiebe, and R. Wiesendanger, Nature Commun. 12, 2040 (2021).
[5] L. Schneider, P. Beck, J. Wiebe, and R. Wiesendanger, Science Advances 7, eabd7302 (2021).
[7] L. Schneider, P. Beck, J. Neuhaus-Steinmetz, T. Posske, J. Wiebe, and R. Wiesendanger, arXiv:2104.11503 [cond-mat.supr-con] (2021)
