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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Magnetic edge states and coherent manipulation of graphene nanoribbons
AU - Slota, Michael
AU - Keerthi, Ashok
AU - Myers, William K.
AU - Tretyakov, Evgeny
AU - Baumgarten, Martin
AU - Ardavan, Arzhang
AU - Sadeghi, Hatef
AU - Lambert, Colin J.
AU - Narita, Akimitsu
AU - Müllen, Klaus
AU - Bogani, Lapo
PY - 2018/5/30
Y1 - 2018/5/30
N2 - Graphene, a single-layer network of carbon atoms, has outstanding electrical and mechanical properties. Graphene ribbons with nanometre-scale widths (nanoribbons) should exhibit half-metallicity and quantum confinement. Magnetic edges in graphene nanoribbons have been studied extensively from a theoretical standpoint because their coherent manipulation would be a milestone for spintronic and quantum computing devices. However, experimental investigations have been hampered because nanoribbon edges cannot be produced with atomic precision and the graphene terminations that have been proposed are chemically unstable. Here we address both of these problems, by using molecular graphene nanoribbons functionalized with stable spin-bearing radical groups. We observe the predicted delocalized magnetic edge states and test theoretical models of the spin dynamics and spin–environment interactions. Comparison with a non-graphitized reference material enables us to clearly identify the characteristic behaviour of the radical-functionalized graphene nanoribbons. We quantify the parameters of spin–orbit coupling, define the interaction patterns and determine the spin decoherence channels. Even without any optimization, the spin coherence time is in the range of microseconds at room temperature, and we perform quantum inversion operations between edge and radical spins. Our approach provides a way of testing the theory of magnetism in graphene nanoribbons experimentally. The coherence times that we observe open up encouraging prospects for the use of magnetic nanoribbons in quantum spintronic devices.
AB - Graphene, a single-layer network of carbon atoms, has outstanding electrical and mechanical properties. Graphene ribbons with nanometre-scale widths (nanoribbons) should exhibit half-metallicity and quantum confinement. Magnetic edges in graphene nanoribbons have been studied extensively from a theoretical standpoint because their coherent manipulation would be a milestone for spintronic and quantum computing devices. However, experimental investigations have been hampered because nanoribbon edges cannot be produced with atomic precision and the graphene terminations that have been proposed are chemically unstable. Here we address both of these problems, by using molecular graphene nanoribbons functionalized with stable spin-bearing radical groups. We observe the predicted delocalized magnetic edge states and test theoretical models of the spin dynamics and spin–environment interactions. Comparison with a non-graphitized reference material enables us to clearly identify the characteristic behaviour of the radical-functionalized graphene nanoribbons. We quantify the parameters of spin–orbit coupling, define the interaction patterns and determine the spin decoherence channels. Even without any optimization, the spin coherence time is in the range of microseconds at room temperature, and we perform quantum inversion operations between edge and radical spins. Our approach provides a way of testing the theory of magnetism in graphene nanoribbons experimentally. The coherence times that we observe open up encouraging prospects for the use of magnetic nanoribbons in quantum spintronic devices.
U2 - 10.1038/s41586-018-0154-7
DO - 10.1038/s41586-018-0154-7
M3 - Journal article
VL - 557
SP - 691
EP - 695
JO - Nature
JF - Nature
SN - 0028-0836
IS - 7707
ER -