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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.
Bibliographical noteFunding Information:
We acknowledge G. Graziano and Y. Ayino for help with using the dilution refrigerator and S. Frolov, Y. Jiang, S. Heedt, X. Fu, X. Ying, and P. Zhang for helpful discussions. This work was supported primarily by the Department of Energy under award no. DE-SC-0019274. Nanowire growth was supported by the European Research Council (ERC HELENA 617256) and the Dutch Organization for Scientific Research (NWO). Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under award no. ECCS-1542202, and in the Characterization Facility, University of Minnesota, a member of the NSF-funded Materials Research Facilities Network ( www.mrfn.org ) via the MRSEC program.
© 2020 American Chemical Society.
- 1D ballistic spin transport
- helical gap
- InSb nanowire
- semiconductor-ferromagnet quantum device
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 7
PubMed: MeSH publication types
- Journal Article