| Autor: |
Leutenantsmeyer, J. C., Ingla-Aynes, J., Fabian, Jaroslav, van Wees, Bart J. |
| Předmět: |
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| Popis: |
We report the first observation of a large spin-lifetime anisotropy in bilayer graphene (BLG) fully encapsulated between hexagonal boron nitride. We characterize the out-of-plane (τ⊥) and in-plane (τ∥) spin lifetimes by oblique Hanle spin precession. At 75 K and the charge neutrality point (CNP), we observe a strong anisotropy of τ⊥/τ∥=8±2. This value is comparable to graphene–transition-metal-dichalcogenide heterostructures, whereas our high-quality BLG provides with τ⊥ up to 9 ns, a spin lifetime more than 2 orders of magnitude larger. The anisotropy decreases to 3.5±1 at a carrier density of n=6×1011 cm−2. Temperature-dependent measurements show above 75 K a decrease of τ⊥/τ∥ with increasing temperature, reaching the isotropic case close to room temperature. We explain our findings with electric-field-induced spin-valley coupling arising from the small intrinsic spin-orbit fields in BLG of 12 μeV at the CNP. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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