title: Reconfigurable nanoantennas using electron-beam manipulation.
abstract: Plasmonic nanoantennas have been of increasing interest due to their ability to confine and enhance electric fields in deep sub-wavelength volumes, leading to large near-field optical forces and high refractive index sensitivity. Recently, to enhance the response for sensor applications, metal nanoantennas have been fabricated on pillars. An overlooked consequence of this elevated geometry is the introduction of the mechanical properties, for example, stiffness, as a tunable degree of freedom. Here we demonstrate pillar-bowtie nanoantenna arrays, fabricated on optically transparent SiO2, as a candidate system that couples intrinsic mechanical and electromagnetic degrees of freedom via gradient forces. We show that using a standard scanning electron microscope, individual nanoantenna gap sizes can be controllably tuned down to 5 nm, a factor of ~4 × smaller than what is currently achievable using conventional electron-beam lithography. This approach opens new avenues for fabricating reconfigurable nanoantennas that can inform exciting photonic applications.
authors.affiliation: 1] Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2].
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Roxworthy
authors.affiliation: 1] Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2].
authors.forename: Abdul M
authors.initials: AM
authors.lastname: Bhuiya
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.affiliation: Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Edmond K C
authors.initials: EK
authors.lastname: Chow
authors.affiliation: Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Kimani C
authors.initials: KC
authors.lastname: Toussaint