Klein scattering of spin-1 Dirac-Weyl wave and localized surface plasmon

Hong-Ya Xu,Ying-Cheng Lai,Liang Huang

doi:10.1103/physrevresearch.3.013284

Hong-Ya Xu, Ying-Cheng Lai + Show 1 more

Open Access

https://doi.org/10.1103/physrevresearch.3.013284

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Abstract

Localized surface plasmon and Klein tunneling resonances are two phenomena that were previously thought to be unrelated, where the former plays an important role in subwavelength optics while the latter is fundamental to relativistic quantum mechanics and physics of Dirac materials. We develop a rigorous theory for spin-1 Dirac-Weyl particles, which establishes a striking analogy between the two phenomena and unveils a deep connection between the distinct physical contexts, paving the way for gate-controlled surface plasmon mimetic electronics as well as for realizing localized spoof plasmons in a scope wider than previously thought. A possible experimental scheme is articulated.

Highlights

Electronic and optical waves share a plethora of phenomena such as interference, diffraction, and resonances
For inhomogeneous systems with Klein scattering and localized surface plasmon, we have demonstrated that the analogy between Dirac spin-1 and surface plasmon physics is almost perfect but in the subwavelength regime ρ = kR 1, where the spatial scale of the scatterer R is much smaller than the incident wavelength 2π /k
We have uncovered a striking analogy between localized surface plasmon modes in optics and Klein scattering resonances of spin-1 Dirac-Weyl waves

Summary

INTRODUCTION

Electronic and optical waves share a plethora of phenomena such as interference, diffraction, and resonances. In the regime of small scatterer size, the resonance formulas, line shapes, spatial patterns of the near-field intensities, and flows or currents in both cases bear a remarkable similarity This finding is surprising because conventionally the Klein effect makes the scalar potential highly transparent [27,28] and provides the underlying mechanism for generating a Veselago lens in Dirac electron optics [29,30,31,32]. Evanescent surface modes requires a complex wave number with physical restrictions such as band-gap opening or a negative permittivity, but our work presents a different route to such modes: They can arise in gapless pseudospin-1 Dirac material systems via the Klein scattering resonance mechanism

RESULTS

Dirac currents and Poynting vectors

Relation to experiments

Effect of next-nearest-neighbor hopping process

DISCUSSION