Spin communication over 30 µ m long channels of chemical vapor deposited graphene on SiO ₂

Abstract

We demonstrate a high-yield fabrication of non-local spin valve devices with roomtemperature spin lifetimes of up to 3 ns and spin relaxation lengths as long as 9 µm in platinum-based chemical vapor deposition (Pt-CVD) synthesized single-layer graphene on SiO 2 /Si substrates. The spin-lifetime systematically presents a marked minimum at the charge neutrality point, as typically observed in pristine exfoliated graphene.However, by studying the carrier density dependence beyond n ~ 5 x 10 12 cm -2 , via electrostatic gating, it is found that the spin lifetime reaches a maximum and then starts decreasing, a behavior that is reminiscent of that predicted when the spinrelaxation is driven by spin-orbit interaction. The spin lifetimes and relaxation lengths compare well with state-of-the-art results using exfoliated graphene on SiO 2 /Si, being a factor two-to-three larger than the best values reported at room temperature using the same substrate. As a result, the spin signal can be readily measured across 30-µm long graphene channels. These observations indicate that Pt-CVD graphene is a promising material for large-scale spin-based logic-in-memory applications.

Tunable room-temperature spin galvanic and spin Hall effects in van der Waals heterostructures

“…Hall cross bar using electron-beam lithography followed by oxygen plasma etching [34]. The resin is then removed with acetone.…”

Thermally Activated Processes for Ferromagnet Intercalation in Graphene-Heavy Metal Interfaces

“…In particular, when Gr is coupled with a FM, a variety of fundamental and technologically relevant effects have been found, such as high spin injection efficiency [7], antiferromagnetic coupling [8], Rashba effect [5] [9], spin filtering [10], tunnel magnetoresistance [11], or enhancement of the magnetic moment perpendicular to the surface [12][13] [14]. More recently, it has been demonstrated that Gr/FM structures allow for RT stable chiral spin textures [13] [15], and preserve spins over large distances and long times [16].…”

Ultimate Spin Currents in Commercial Chemical Vapor Deposited Graphene

“…Recently, spin diffusion lengths λ of ∼7–9 μm and spin lifetimes τ of ∼2–3 ns were reported in special CVD graphene grown over a Pt substrate. 12 This performance is higher than the previously obtained best values in CVD graphene grown on Cu substrates. 3 It has been reported that a platinum substrate facilitates high-temperature (1100 °C) nucleation and crystallization, resulting in millimeter-sized CVD graphene crystals.…”

“…e ., the experimentally demonstrated distance over which spin currents can propagate, is nearly 300% longer compared to the spin communication achieved with the highest spin parameters in commercial CVD graphene 3 and significantly higher than the state-of-the-art reports using a Pt-based CVD graphene system. 12 …”