Graphene is an ideal medium for long-distance spin communication in future spintronic technologies. So far, the prospect is limited by the smaller sizes of exfoliated graphene flakes and lower spin transport properties of large-area chemical vapour-deposited (CVD) graphene. Here we demonstrate a high spintronic performance in CVD graphene on SiO₂/Si substrate at room temperature. We show pure spin transport and precession over long channel lengths extending up to 16 μm with a spin lifetime of 1.2 ns and a spin diffusion length ∼ 6 μm at room temperature. These spin parameters are up to six times higher than previous reports and highest at room temperature for any form of pristine graphene on industrial standard SiO₂/Si substrates. Our detailed investigation reinforces the observed performance in CVD graphene over wafer scale and opens up new prospects for the development of lateral spin-based memory and logic applications.

The van der Waals heterostructures of two-dimensional (2D) atomic crystals constitute a new paradigm in nanoscience. Hybrid devices of graphene with insulating 2D hexagonal boron nitride (h-BN) have emerged as promising nanoelectronic architectures through demonstrations of ultrahigh electron mobilities and charge-based tunnel transistors. Here, we expand the functional horizon of such 2D materials demonstrating the quantum tunneling of spin polarized electrons through atomic planes of CVD grown h-BN. We report excellent tunneling behavior of h-BN layers together with tunnel spin injection and transport in graphene using ferromagnet/h-BN contacts. Employing h-BN tunnel contacts, we observe enhancements in both spin signal amplitude and lifetime by an order of magnitude. We demonstrate spin transport and precession over micrometer-scale distances with spin lifetime up to 0.46 nanosecond. Our results and complementary magnetoresistance calculations illustrate that CVD h-BN tunnel barrier provides a reliable, reproducible and alternative approach to address the conductivity mismatch problem for spin injection into graphene.

Two-dimensional (2D) materials have brought fresh prospects for spintronics, as evidenced by the rapid scientific progress made in this frontier over the past decade. In particular, for charge perpendicular to plane vertical magnetic tunnel junctions, the 2D crystals present exclusive features such as atomic-level thickness control, near-perfect crystallography without dangling bonds, and novel electronic structure-guided interfaces with tunable hybridization and proximity effects, which lead to an entirely new group of spinterfaces. Such crystals also present new ways of integration of atomically thin barriers in magnetic tunnel junctions and an unprecedented means for developing composite barriers with atomic precision. All these new aspects have sparked interest for theoretical and experimental efforts, revealing intriguing spin-dependent transport and spin inversion effects. Here, we discuss some of the distinctive effects observed in ferromagnetic junctions with prominent 2D crystals such as graphene, hexagonal boron nitride, and transition metal dichalcogenides and how spinterface phenomena at such junctions affect the observed magnetoresistance in devices. Finally, we discuss how the recently emerged 2D ferromagnets bring upon an entirely novel category of van der Waals interfaces for efficient spin transmission and dynamic control through exotic heterostructures.