title: Defect-Free Carbon Nanotube Coils.
abstract: Carbon nanotubes are promising building blocks for various nanoelectronic components. A highly desirable geometry for such applications is a coil. However, coiled nanotube structures reported so far were inherently defective or had no free ends accessible for contacting. Here we demonstrate the spontaneous self-coiling of single-wall carbon nanotubes into defect-free coils of up to more than 70 turns with identical diameter and chirality, and free ends. We characterize the structure, formation mechanism, and electrical properties of these coils by different microscopies, molecular dynamics simulations, Raman spectroscopy, and electrical and magnetic measurements. The coils are highly conductive, as expected for defect-free carbon nanotubes, but adjacent nanotube segments in the coil are more highly coupled than in regular bundles of single-wall carbon nanotubes, owing to their perfect crystal momentum matching, which enables tunneling between the turns. Although this behavior does not yet enable the performance of these nanotube coils as inductive devices, it does point a clear path for their realization. Hence, this study represents a major step toward the production of many different nanotube coil devices, including inductors, electromagnets, transformers, and dynamos.
authors.forename: Nitzan
authors.initials: N
authors.lastname: Shadmi
authors.affiliation: Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel.
authors.forename: Anna
authors.initials: A
authors.lastname: Kremen
authors.affiliation: Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel.
authors.forename: Yiftach
authors.initials: Y
authors.lastname: Frenkel
authors.affiliation: ETH Zürich , Photonics Laboratory, Zürich, 8093, Switzerland.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Lapin
authors.affiliation: Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas , C. P. 6165, 13083-970 Campinas, Sao Paulo, Brazil.
authors.forename: Leonardo D
authors.initials: LD
authors.lastname: Machado
authors.affiliation: Departamento de Fisica, CCT, Universidade Federal de Roraima , 69304-000 Boa Vista, Roraima, Brazil.
authors.forename: Sergio B
authors.initials: SB
authors.lastname: Legoas
authors.forename: Ora
authors.initials: O
authors.lastname: Bitton
authors.forename: Katya
authors.initials: K
authors.lastname: Rechav
authors.forename: Ronit
authors.initials: R
authors.lastname: Popovitz-Biro
authors.affiliation: Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas , C. P. 6165, 13083-970 Campinas, Sao Paulo, Brazil.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Galvão
authors.affiliation: Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, MG 31270-901, Brazil.
authors.forename: Ado
authors.initials: A
authors.lastname: Jorio
authors.affiliation: ETH Zürich , Photonics Laboratory, Zürich, 8093, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Novotny
authors.affiliation: Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel.
authors.forename: Beena
authors.initials: B
authors.lastname: Kalisky
authors.forename: Ernesto
authors.initials: E
authors.lastname: Joselevich
keywords: CNT; SWNT; guided growth; horizontal CNTs