Strong bonding magnetic plasmon hybridizations in double split-ring resonators

Anomalous plasmon hybridization in nanoantennas near interfaces

We report on an anomalous plasmon hybridization in side-by-side coupled metallic nanoantennas on top of a silicon waveguide. Contrary to the conventional perception based on Coulomb coupling, the hybridized anti-symmetric mode in our structure possesses a higher resonance frequency than the symmetric mode. This unusual phenomenon reveals a new mechanism of plasmon hybridization, namely, coupling-induced charge redistribution. Our work includes numerical simulation, experimental validation, and theoretical analysis, emphasizing the importance of dielectric interfaces in coupled plasmonic structures, and offers new possibilities for non-Hermitian systems and integrated devices.

Plasmon-Induced Transparency by Hybridizing Concentric-Twisted Double Split Ring Resonators

As a classical analogue of electromagnetically induced transparency, plasmon induced transparency (PIT) has attracted great attention by mitigating otherwise cumbersome experimental implementation constraints. Here, through theoretical design, simulation and experimental validation, we present a novel approach to achieve and control PIT by hybridizing two double split ring resonators (DSRRs) on flexible polyimide substrates. In the design, the large rings in the DSRRs are stationary and mirror images of each other, while the small SRRs rotate about their center axes. Counter-directional rotation (twisting) of the small SRRs is shown to lead to resonance shifts, while co-directional rotation results in splitting of the lower frequency resonance and emergence of a PIT window. We develop an equivalent circuit model and introduce a mutual inductance parameter M whose sign is shown to characterize the existence or absence of PIT response from the structure. This model attempts to provide a quantitative measure of the physical mechanisms underlying the observed PIT phenomenon. As such, our findings can support the design of several applications such as optical buffers, delay lines, and ultra-sensitive sensors.

Resonance modes in stereometamaterial of square split ring resonators connected by sharing the gap

Stereometamaerials can fully utilize the 3D degrees of freedom to exploit the coupling and hybridization between multiple split ring resonators (SRRs), enabling more extraordinary resonances and properties over their planar counterparts. Here we propose and numerically study a kind of structure based on connected SRRs sharing their gap in a rotational fashion. It is shown that there are three typical resonance modes in such cage-like SRR (C-SRR) stereometamaterial in the communication and near infrared range. In the order of increasing energy, these modes can be essentially ascribed to magnetic torodial dipole, magnetic dipole, and a mixture of electric-dipole and magnetic toroidal dipole. We show that the latter two are derived from the second-order mode in the corresponding individual SRR, while the first one from the fundamental one. The highest energy mode remains relatively "dark" in an individual C-SRR due to the high-order feature and the rotational symmetry. However, they are all easily excitable in a C-SRR array, offering multiband filtering functionality.