STEM/EELS Imaging of Magnetic Hybridization in Symmetric and Symmetry-Broken Plasmon Oligomer Dimers and All-Magnetic Fano Interference.
Negative-index metamaterials composed of magnetic plasmon oligomers are actively being investigated for their potential role in optical cloaking, superlensing, and nanolithography applications. A significant improvement to their practicality lies in the ability to function at multiple distinct wavelengths in the visible part of spectrum. Here we utilize the nanometer spatial-resolving power of electron energy-loss spectroscopy to conclusively demonstrate hybridization of magnetic plasmons in oligomer dimers that can achieve this goal. We also show that breaking the dimer's symmetry can induce all-magnetic Fano interferences based solely on the interplay of bright and dark magnetic modes, allowing us to further tailor the system's optical responses. These features are engineered through the design of the oligomer's underlying nanoparticle elements as elongated Ag nanodisks with spectrally isolated long-axis plasmon resonances. The resulting magnetic plasmon oligomers and their hybridized assemblies establish a new design paradigm for optical metamaterials with rich functionality.
Charles
C
Cherqui
Department of Materials Science and Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States.
Yueying
Y
Wu
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Guoliang
G
Li
Steven C
SC
Quillin
Jacob A
JA
Busche
Niket
N
Thakkar
Claire A
CA
West
Nicholas P
NP
Montoni
Department of Materials Science and Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Philip D
PD
Rack
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Jon P
JP
Camden
David J
DJ
Masiello
Electron energy-loss spectroscopy; Fano interference; magnetic plasmon oligomers; metamaterials