Enhanced spin–orbit coupling in dilute fluorinated graphene. (10th November 2015)

• Record Type: Journal Article
• Authors: Avsar, Ahmet; Hak Lee, Jong; Koon, Gavin Kok Wai; Özyilmaz, Barbaros
• Is Part Of: 2D materials. Volume 2:Number 4(2015)
• Publication Date: 2015-11-10
• Subjects: fluorinated graphene -- spin orbit coupling -- spin Hall effect -- spin transport; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/2/4/044009
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: The preservation and manipulation of a spin state mainly depends on the strength of the spin–orbit interaction. For pristine graphene, the intrinsic spin–orbit coupling (SOC) is only in the order of few μ eV, which makes it almost impossible to be used as an active element in future electric field controlled spintronics devices. This stimulates the development of a systematic method for extrinsically enhancing the SOC of graphene. In this letter, we study the strength of SOC in weakly fluorinated graphene devices. We observe high non-local signals even without applying any external magnetic field. The magnitude of the signal increases with increasing fluorine adatom coverage. From the length dependence of the non-local transport measurements, we obtain SOC values of ∼5.1 meV and ∼9.1 meV for the devices with ∼0.005% and ∼0.06% fluorination, respectively. Such a large enhancement, together with the high charge mobility of fluorinated samples ( μ ∼ 4300 cm 2 V −1 s −1 –2700 cm 2 V −1 s −1 ), enables the detection of the spin Hall effect even at room temperature.