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