Leutenantsmeyer, Johannes Christian and Ingla-Aynes, Josep and Fabian, Jaroslav and van Wees, Bart J. (2018) Observation of Spin-Valley-Coupling-Induced Large Spin-Lifetime Anisotropy in Bilayer Graphene. PHYSICAL REVIEW LETTERS, 121 (12): 127702. ISSN 0031-9007, 1079-7114
Full text not available from this repository. (Request a copy)Abstract
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 (tau(perpendicular to)) and in-plane (tau(parallel to)) spin lifetimes by oblique Hanle spin precession. At 75 K and the charge neutrality point (CNP), we observe a strong anisotropy of tau(perpendicular to)/tau(parallel to) = 8 +/- 2. This value is comparable to graphene-transition-metal-dichalcogenide heterostructures, whereas our high-quality BLG provides with tau(perpendicular to) 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 x 10(11) cm(-2). Temperature-dependent measurements show above 75 K a decrease of tau(perpendicular to)/tau(parallel to) 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 mu eV at the CNP.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RELAXATION; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Jaroslav Fabian |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 12 Dec 2019 14:30 |
| Last Modified: | 12 Dec 2019 14:30 |
| URI: | https://pred.uni-regensburg.de/id/eprint/13843 |
Actions (login required)
 |
View Item |
