Ultraslow waves on the nanoscale

Abstract

There has recently been a surge of interest in the physics and applications of broadband ultraslow waves in nanoscale structures operating below the diffraction limit. They range from lightwaves or surface plasmons in nanoplasmonic devices to sound waves in acoustic-metamaterial waveguides, as well as fermions and phonon polaritons in graphene and van der Waals crystals and heterostructures. We review the underlying physics of these structures, which upend traditional wave-slowing approaches based on resonances or on periodic configurations above the diffraction limit. Light can now be tightly focused on the nanoscale at intensities up to ~1000 times larger than the output of incumbent near-field scanning optical microscopes, while exhibiting greatly boosted density of states and strong wave-matter interactions. We elucidate the general methodology by which broadband and, simultaneously, large wave-decelerations, well below the diffraction limit, can be obtained in the above interdisciplinary fields. We also highlight a range of applications for renewable energy, biosensing, quantum optics, highdensity magnetic data-storage and nanoscale chemical mapping.

Rainbow Trapping with Long Oscillation Lifetimes in Gradient Magnetoinductive Metasurfaces

“…Most previous works can be classified as dispersion engineering, where waveguides with tailored dispersion characteristics are the key to make waves of different wavelengths halt at desirable positions. Gratings were widely utilized to slow down surface plasmons to a * 230159363@seu.edu.cn † shijun@caltech.edu ‡ 101010074@seu.edu.cn § dsievenpiper@eng.ucsd.edu standstill to obtain rainbow trapping [18][19][20][21]. Similar phenomena were also reported in photonic crystals [22][23][24] as well as metal-insulator-metal tapered plasmonic waveguides [16].…”

Computing one-dimensional metasurfaces

“…This is a relatively trivial instance of slow light, which has been thoroughly discussed in Ref. [28].…”

Quasielectrostatic Wave Propagation Beyond the Delay-Bandwidth Limit in Switched Networks

“…In electromagnetics, the use of spatial modulation enables a large degree of control over the phase and group velocities, polarization, and amplitude of traveling waves. Examples of such manipulation include extreme light traveling regimes, such as propagation with ultralow (v g ≪ c) and superluminal (v g > c) group velocities [1][2][3][4][5]. Based on these principles, it has been shown that it is possible to bring a light pulse to a near standstill [6][7][8].…”