posted on 2016-11-17, 00:00authored byDiana Car, Sonia Conesa-Boj, Hao Zhang, Roy L. M. Op het Veld, Michiel W. A. de Moor, Elham M. T. Fadaly, Önder Gül, Sebastian Kölling, Sebastien R. Plissard, Vigdis Toresen, Michael T. Wimmer, Kenji Watanabe, Takashi Taniguchi, Leo P. Kouwenhoven, Erik P. A. M. Bakkers
Majorana
zero modes (MZMs), prime candidates for topological quantum bits,
are detected as zero bias conductance peaks (ZBPs) in tunneling spectroscopy
measurements. Implementation of a narrow and high tunnel barrier in
the next generation of Majorana devices can help to achieve the theoretically
predicted quantized height of the ZBP. We propose a material-oriented
approach to engineer a sharp and narrow tunnel barrier by synthesizing
a thin axial segment of GaxIn1–xSb within an InSb nanowire. By varying the precursor
molar fraction and the growth time, we accurately control the composition
and the length of the barriers. The height and the width of the GaxIn1–xSb
tunnel barrier are extracted from the Wentzel–Kramers-Brillouin
(WKB) fits to the experimental I–V traces.