Electronic transport in quantum InSb nanowire spin-valve devices*

Semiconductor nanowires (NWs) with strong spin-orbital interaction, such as InSb NWs, are a leading platform in realizing future Majorana zero modes based quantum computing devices. However, the need for applying external magnetic fields can suppress the superconductivity and place geometric restrictions on the device. Hybrid magnet-nanowire devices can help to circumvent this issue. To study the integration of ferromagnetic materials, we fabricated InSb NW spin-valve devices and investigated spin transport. Spin-polarized transport leads to hysteretic magnetoconductance, which can be tuned through electrostatic gating. We find that the transport is phase-coherent and, for contact spacings of a few hundred nanometers, also quasi-ballistic¹. In the few modes regime, we observe a strong modulation of conductance with gating, accompanied by a distinct magnetoconductance hysteresis, suggesting that the device acts as a spin filter. Our results present a path for realizing Majorana modes without the need to apply external magnetic fields and could be relevant for developing quantum spintronic devices based on semiconductor nanowires.
1. Yang, Z. et al. Nano Lett. 20, 3232–3239 (2020).