One-dimensional ferromagnetic edge contacts to two-dimensional graphene/h-BN heterostructures

Abstract

We report the fabrication of one-dimensional (1D) ferromagnetic edge contacts to two-dimensional (2D) graphene/h-BN heterostructures. While aiming to study spin injection/detection with 1D edge contacts, a spurious magnetoresistance signal was observed, which is found to originate from the local Hall effect in graphene due to fringe fields from ferromagnetic edge contacts and in the presence of charge current spreading in the nonlocal measurement configuration. Such behavior has been confirmed by the absence of a Hanle signal and gate-dependent magnetoresistance measurements that reveal a change in sign of the signal for the electron- and hole-doped regimes, which is in contrast to the expected behavior of the spin signal. Calculations show that the contact-induced fringe fields are typically on the order of hundreds of mT, but can be reduced below 100 mT with careful optimization of the contact geometry. There may be additional contribution from magnetoresistance effects due to tunneling anisotropy in the contacts, which need to be further investigated. These studies are useful for optimization of spin injection and detection in 2D material heterostructures through 1D edge contacts.

References in corpus (18)

• The Raman Fingerprint of Graphene
• Half-Metallic Graphene Nanoribbons
• Electronic spin transport and spin precession in single graphene layers at room temperature
• Graphene Spintronics
• Hunting for Monolayer Boron Nitride: Optical and Raman Signatures
• Tunneling Spin Injection into Single Layer Graphene (Supplementary Information)
• Tunneling Spin Injection into Single Layer Graphene
• Highly efficient spin transport in epitaxial graphene on SiC
• Tunneling Anisotropic Magnetoresistance: A spin-valve like tunnel magnetoresistance using a single magnetic layer
• Spin currents in rough graphene nanoribbons: Universal fluctuations and spin injection
• Spin lifetimes exceeding 12 nanoseconds in graphene non-local spin valve devices
• Spin precession and inverted Hanle effect in a semiconductor near a finite-roughness ferromagnetic interface
• Tunneling anisotropic magnetoresistance in multilayer-(Co/Pt)/AlOx/Pt structures
• 24 \textmu m length spin relaxation length in boron nitride encapsulated bilayer graphene
• Spin Transport and Precession in Graphene measured by Nonlocal and Three-Terminal Methods
• Gate-tunable Hall sensors on large area CVD graphene protected by h-BN with 1D edge contacts
• Tunneling Anisotropic Magnetoresistance in Co/AlOx/Au Tunnel Junctions
• Large local Hall effect in pin-hole dominated multigraphene spin-valves

Cited by in corpus (14)

• Colloquium: Spintronics in graphene and other two-dimensional materials
• One-dimensional edge contacts to a monolayer semiconductor
• Spin inversion in graphene spin valves by gate-tunable magnetic proximity effect at one-dimensional contacts
• Electrical spin injection, transport, and detection in graphene-hexagonal boron nitride van der Waals heterostructures: progress and perspectives
• Two-Dimensional Spintronic Circuit Architectures on Large Scale Graphene
• Tuneable spin injection in high-quality graphene with one-dimensional contacts
• Charge to Spin Conversion in van der Waals Metal NbSe2
• All-electrical creation and control of giant spin-galvanic effect in 1T-MoTe2/graphene heterostructures at room temperature
• Room temperature nonlocal detection of charge-spin interconversion in a topological insulator
• Charge-induced artifacts in non-local spin transport measurements: How to prevent spurious voltage signals
• Oblique spin injection to graphene via geometry controlled magnetic nanowires
• Spin polarised quantised transport via one-dimensional nanowire-graphene contacts
• Large spin signal and spin rectification in folded-bilayer graphene
• Giant Spin Transport Anisotropy in Magnetic Topological Insulators