Spin Transport in Ferromagnet-InSb Nanowire Quantum Devices

• Published in: Nano letters 2020-05, Vol.20 (5), p.3232-3239
• Main Authors: Yang, Zedong, Heischmidt, Brett, Gazibegovic, Sasa, Badawy, Ghada, Car, Diana, Crowell, Paul A, Bakkers, Erik P.A.M, Pribiag, Vlad S
• Format: Article
• Language: English
• Subjects: 1D ballistic spin transport; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; helical gap; InSb nanowire; MATERIALS SCIENCE; NANOSCIENCE AND NANOTECHNOLOGY; semiconductor-ferromagnet quantum device
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.9b05331

Signatures of Majorana zero modes (MZMs) have been observed in semiconductor nanowires (NWs) with a strong spin–orbital interaction (SOI) with proximity-induced superconductivity. Realizing topological superconductivity and MZMs in this platform requires eliminating spin degeneracy by applying a magnetic field. However, the field can adversely impact the induced superconductivity and places geometric restrictions on the device. These challenges could be circumvented by integrating magnetic elements with the NWs. Here, we report the first experimental investigation of spin transport across InSb NWs with ferromagnetic (FM) contacts. We observe signatures of spin polarization and spin-dependent transport in the quasi-one-dimensional ballistic regime. Moreover, we show that electrostatic gating tunes the observed magnetic signal and reveals a regime where the device acts as a spin filter. These results open an avenue toward developing MZM devices with spin degeneracy lifted locally without external fields. They could also enable spin-based devices that leverage spin–orbital states in quantum wires.