title: Single-Atom Switches and Single-Atom Gaps Using Stretched Metal Nanowires.
abstract: Utilizing individual atoms or molecules as functional units in electronic circuits meets the increasing technical demands for the miniaturization of traditional semiconductor devices. To be of technological interest, these functional devices should be high-yield, consume low amounts of energy, and operate at room temperature. In this study, we developed nanodevices called quantized conductance atomic switches (QCAS) that satisfy these requirements. The QCAS operates by applying a feedback-controlled voltage to a nanoconstriction within a stretched nanowire. We demonstrated that individual metal atoms could be removed from the nanoconstriction and that the removed metal atoms could be refilled into the nanoconstriction, thus yielding a reversible quantized conductance switch. We determined the key parameters for the QCAS between the "on" and "off" states at room temperature under a small operating voltage. By controlling the applied bias voltage, the atoms can be further completely removed from the constriction to break the nanowire, generating single-atom nanogaps. These atomic nanogaps are quite stable under a sweeping voltage and can be readjusted with subangstrom accuracy, thus fulfilling the requirement of both reliability and flexibility for the high-yield fabrication of molecular devices.
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Physics and Electronics, Shandong Normal University , Jinan 250014, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Liu
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Mingyu
authors.initials: M
authors.lastname: Sun
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Zhikai
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Sun
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.|Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea.
authors.forename: Tingting
authors.initials: T
authors.lastname: Mei
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Wu
authors.affiliation: Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Guo
authors.affiliation: College of Physics and Electronics, Shandong Normal University , Jinan 250014, China.
authors.forename: Zong-Liang
authors.initials: ZL
authors.lastname: Li
authors.affiliation: Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea.
authors.forename: Takhee
authors.initials: T
authors.lastname: Lee
keywords: electromigration; molecular devices; molecular electronics; nanogaps; quantized conductance switches; single-atom memory