title: Sub-nanosecond signal propagation in anisotropy-engineered nanomagnetic logic chains.
abstract: Energy efficient nanomagnetic logic (NML) computing architectures propagate binary information by relying on dipolar field coupling to reorient closely spaced nanoscale magnets. Signal propagation in nanomagnet chains has been previously characterized by static magnetic imaging experiments; however, the mechanisms that determine the final state and their reproducibility over millions of cycles in high-speed operation have yet to be experimentally investigated. Here we present a study of NML operation in a high-speed regime. We perform direct imaging of digital signal propagation in permalloy nanomagnet chains with varying degrees of shape-engineered biaxial anisotropy using full-field magnetic X-ray transmission microscopy and time-resolved photoemission electron microscopy after applying nanosecond magnetic field pulses. An intrinsic switching time of 100 ps per magnet is observed. These experiments, and accompanying macrospin and micromagnetic simulations, reveal the underlying physics of NML architectures repetitively operated on nanosecond timescales and identify relevant engineering parameters to optimize performance and reliability.
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gu
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Nowakowski
authors.affiliation: Intel Corp., 2200 Mission College Boulevard, Santa Clara, California 95054, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Carlton
authors.affiliation: Thorlabs Inc., 56 Sparta Avenue, Newton, New Jersey 07860, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Storz
authors.affiliation: 1] Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA [2] Daegu Gyeongbuk Institute of Science and Technology, Daegu 711-873, Korea.
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Im
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Jeongmin
authors.identifier: 0000000286393620
authors.initials: J
authors.lastname: Hong
authors.affiliation: Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Weilun
authors.initials: W
authors.lastname: Chao
authors.affiliation: iRunway, 2906 Stender Way, Santa Clara, California 95054, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Lambson
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bennett
authors.affiliation: Intel Corp., 5200 NE Elam Young Parkway, Hillsboro, Oregon 97124, USA.
authors.forename: Mohmmad T
authors.initials: MT
authors.lastname: Alam
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Marcus
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Doran
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Young
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Scholl
authors.affiliation: 1] Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA [2] Department of Physics, University of California, Santa Cruz, California 94056, USA.
authors.forename: Peter
authors.identifier: 0000000298249343
authors.initials: P
authors.lastname: Fischer
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bokor