Plasmonic epsilon-near-zero (ENZ) engineering for electron-phonon interaction (EPI)

Electron scattering in a general solid-state material consisting of electrons, phonons, impurities, etc. could be viewed as scattering by a screened Coulomb potential with a total epsilon packing up contributions from all the components [1,2,3,4]. Wherever there is a singularity in the imaginary part of one over epsilon, i.e., the condition of epsilon near zero (ENZ) [6], there is a mode (collective excitation) in the system [5]. We show in this context, as a prototype, that electron-polar-optical-phonon scattering could be quenched by an additional fine-tuned plasmonic resonance introduced to the system. This could serve as a general engineering trick which might have applications in many fields. The physics picture is, polarization of the newly added resonance, with frequency and strength fine-tuned, could destructively interfere with and cancel out polarization of the original resonance of the system.

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