TY - JOUR
T1 - Subgap spectroscopy along hybrid nanowires by nm-thick tunnel barriers
AU - Levajac, Vukan
AU - Wang, Ji Yin
AU - Sfiligoj, Cristina
AU - Lemang, Mathilde
AU - Wolff, Jan Cornelis
AU - Bordin, Alberto
AU - Badawy, Ghada
AU - Gazibegovic, Sasa
AU - Bakkers, Erik P.A.M.
AU - Kouwenhoven, Leo P.
PY - 2023
Y1 - 2023
N2 - Tunneling spectroscopy is widely used to examine the subgap spectra in semiconductor-superconductor nanostructures when searching for Majorana zero modes (MZMs). Typically, semiconductor sections controlled by local gates at the ends of hybrids serve as tunnel barriers. Besides detecting states only at the hybrid ends, such gate-defined tunnel probes can cause the formation of non-topological subgap states that mimic MZMs. Here, we develop an alternative type of tunnel probes to overcome these limitations. After the growth of an InSb-Al hybrid nanowire, a precisely controlled in-situ oxidation of the Al shell is performed to yield a nm-thick AlOx layer. In such thin isolating layer, tunnel probes can be arbitrarily defined at any position along the hybrid nanowire by shadow-wall angle-deposition of metallic leads. In this work, we make multiple tunnel probes along single nanowire hybrids and successfully identify Andreev bound states (ABSs) of various spatial extension residing along the hybrids.
AB - Tunneling spectroscopy is widely used to examine the subgap spectra in semiconductor-superconductor nanostructures when searching for Majorana zero modes (MZMs). Typically, semiconductor sections controlled by local gates at the ends of hybrids serve as tunnel barriers. Besides detecting states only at the hybrid ends, such gate-defined tunnel probes can cause the formation of non-topological subgap states that mimic MZMs. Here, we develop an alternative type of tunnel probes to overcome these limitations. After the growth of an InSb-Al hybrid nanowire, a precisely controlled in-situ oxidation of the Al shell is performed to yield a nm-thick AlOx layer. In such thin isolating layer, tunnel probes can be arbitrarily defined at any position along the hybrid nanowire by shadow-wall angle-deposition of metallic leads. In this work, we make multiple tunnel probes along single nanowire hybrids and successfully identify Andreev bound states (ABSs) of various spatial extension residing along the hybrids.
UR - http://www.scopus.com/inward/record.url?scp=85174521035&partnerID=8YFLogxK
U2 - 10.1038/s41467-023-42422-z
DO - 10.1038/s41467-023-42422-z
M3 - Article
C2 - 37863952
AN - SCOPUS:85174521035
SN - 2041-1723
VL - 14
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 6647
ER -