Tuneable spin injection in high-quality graphene with one-dimensional contacts

Abstract

Spintronics involves the development of low-dimensional electronic systems with potential use in quantum-based computation. In graphene, there has been significant progress in improving spin transport characteristics by encapsulation and reducing impurities, but the influence of standard two-dimensional (2D) tunnel contacts, via pinholes and doping of the graphene channel, remains difficult to eliminate. Here, we report the observation of spin injection and tuneable spin signal in fully-encapsulated graphene, enabled by van der Waals heterostructures with one-dimensional (1D) contacts. This architecture prevents significant doping from the contacts, enabling high-quality graphene channels, currently with mobilities up to 130,000 cm${}^2$V${}^{-1}$s${}^{-1}$ and spin diffusion lengths approaching 20 $\mu$m. The nanoscale-wide 1D contacts allow spin injection both at room and at low temperature, with the latter exhibiting efficiency comparable with 2D tunnel contacts. At low temperature, the spin signals can be enhanced by as much as an order of magnitude by electrostatic gating, adding new functionality.

Manuscript and Supporting Information

References in corpus (10)

• The electronic properties of graphene
• Micrometer-scale ballistic transport in encapsulated graphene at room temperature
• Graphene Spintronics
• Tunneling Spin Injection into Single Layer Graphene (Supplementary Information)
• Tunneling Spin Injection into Single Layer Graphene
• Electronic spin drift in graphene field effect transistors
• Spin transport in high quality suspended graphene devices
• Contact induced spin relaxation in Hanle spin precession measurements
• Nanosecond spin relaxation times in single layer graphene spin valves with hexagonal boron nitride tunnel barriers
• Contact-induced charge contributions to non-local spin transport measurements in Co/MgO/graphene devices

Cited by in corpus (6)

• Thermopower in hBN/graphene/hBN superlattices
• Exploring room temperature spin transport under band gap opening in bilayer graphene
• On the angular dependence of anomalous Hall current
• Oblique spin injection to graphene via geometry controlled magnetic nanowires
• Large spin signal and spin rectification in folded-bilayer graphene
• Spin polarised quantised transport via one-dimensional nanowire-graphene contacts