title: Giant spin Hall effect in graphene grown by chemical vapour deposition.
abstract: Advances in large-area graphene synthesis via chemical vapour deposition on metals like copper were instrumental in the demonstration of graphene-based novel, wafer-scale electronic circuits and proof-of-concept applications such as flexible touch panels. Here, we show that graphene grown by chemical vapour deposition on copper is equally promising for spintronics applications. In contrast to natural graphene, our experiments demonstrate that chemically synthesized graphene has a strong spin-orbit coupling as high as 20 meV giving rise to a giant spin Hall effect. The exceptionally large spin Hall angle ~0.2 provides an important step towards graphene-based spintronics devices within existing complementary metal-oxide-semiconductor technology. Our microscopic model shows that unavoidable residual copper adatom clusters act as local spin-orbit scatterers and, in the resonant scattering limit, induce transverse spin currents with enhanced skew-scattering contribution. Our findings are confirmed independently by introducing metallic adatoms-copper, silver and gold on exfoliated graphene samples.
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3] [4].
authors.forename: Jayakumar
authors.initials: J
authors.lastname: Balakrishnan
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3] Nanocore, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore [4].
authors.forename: Gavin Kok Wai
authors.initials: GK
authors.lastname: Koon
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Avsar
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Nanocore, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore.
authors.forename: Yuda
authors.initials: Y
authors.lastname: Ho
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Jong Hak
authors.initials: JH
authors.lastname: Lee
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3].
authors.forename: Manu
authors.initials: M
authors.lastname: Jaiswal
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Korea.
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Baeck
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3] Instituto de Física, Universidade Federal Fluminense, Niterói, 24210-346 Rio de Janeiro, Brazil.
authors.forename: Aires
authors.initials: A
authors.lastname: Ferreira
authors.affiliation: 1] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [2] Department of Physics, National Tsing Hua University, Hsinchu City 30013, Taiwan.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cazalilla
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Antonio H
authors.initials: AH
authors.lastname: Castro Neto
authors.affiliation: 1] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [2] Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3] Nanocore, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore.
authors.forename: Barbaros
authors.initials: B
authors.lastname: Özyilmaz