title: Single-ion adsorption and switching in carbon nanotubes.
abstract: Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes, by the mechanism of ion potential-induced carrier depletion, which is supported by density functional and Landauer transport theory. Our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.
authors.affiliation: Physical Sciences Laboratories, The Aerospace Corporation, 355 S. Douglas Street, El Segundo, California 90245, USA.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Bushmaker
authors.affiliation: Physical Sciences Laboratories, The Aerospace Corporation, 355 S. Douglas Street, El Segundo, California 90245, USA.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Oklejas
authors.affiliation: Physical Sciences Laboratories, The Aerospace Corporation, 355 S. Douglas Street, El Segundo, California 90245, USA.
authors.forename: Don
authors.initials: D
authors.lastname: Walker
authors.affiliation: Physical Sciences Laboratories, The Aerospace Corporation, 355 S. Douglas Street, El Segundo, California 90245, USA.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Hopkins
authors.affiliation: Department of Electrical Engineering, The University of Southern California, 3601 Watt Way, Los Angeles, California 90089, USA.
authors.forename: Jihan
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Electrical Engineering, The University of Southern California, 3601 Watt Way, Los Angeles, California 90089, USA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Cronin