Perfect absorption by metal-contacted two-dimensional systems with ultra-proximate reflectors
Abstract
Electromagnetic absorbance by most two-dimensional electron systems is typically well below unity, which hinders both practical applications in photodetection and fundamental studies of their optical properties. Here, we show that a periodic structure comprised of narrow two-dimensional sections connected with wide perfectly conducting metal sections enables large absorbance. It reaches 50 \% provided the filling factor by the two-dimensional system f equals its dimensionless conductivity η=σZ0/2, where Z0 is the free-space impedance. The absorbance is further raised to 100 \% if the periodic structure is placed above a perfectly conducting electromagnetic reflector, and provided f=2η. Surprisingly, the optimal distance between two-dimensional system and reflector may fall well below the quarter of incident wavelength λ0/4, which was assumed as conventional absorption enhancement condition in optics. For low filling factors f≪1, large dielectric constants of the substrate, and grating periods comparable with λ0, the optimal distance to reflector tends to zero. Above the critical values of the grating geometrical parameters, the absorbance maximum ceases to exist. The critical behavior manifests as a large-amplitude resonance in 'dirty' two-dimensional system with purely real conductivity, while enhancement of carrier momentum relaxation time lowers the resonant peak. Such resonance mimics the plasmonic one, but does not rely on high electron mobility.
Versions
Related
- Coherent perfect absorption in non-Hermitian dimers
- Boundary-induced medium mapping enables air-equivalent acoustic propagation and perfect absorption in water
- All-optical control of coherent perfect absorption via frequency conversion
- Massively Degenerate Coherent Perfect Absorption in Gradient-Index Fibers
- Boundary singular scattering enables coherent perfect absorption and lasing without resonators
BibTeX
@misc{kapralov2026perfect,
title = {{Perfect absorption by metal-contacted two-dimensional systems with ultra-proximate reflectors}},
author = {Kirill Kapralov and Vladislav Atlasov and Alina Khisameeva and Viacheslav Muravev and Dmitry Svintsov},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.07218},
eprint = {2608.07218},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.07218},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Perfect absorption by metal-contacted two-dimensional systems with ultra-proximate reflectors
AU - Kirill Kapralov
AU - Vladislav Atlasov
AU - Alina Khisameeva
AU - Viacheslav Muravev
AU - Dmitry Svintsov
PY - 2026
DA - 2026/08/07
PB - arXiv
DO - 10.48550/arxiv.2608.07218
UR - https://arxiv.org/abs/2608.07218
AB - Electromagnetic absorbance by most two-dimensional electron systems is typically well below unity, which hinders both practical applications in photodetection and fundamental studies of their optical properties. Here, we show that a periodic structure comprised of narrow two-dimensional sections connected with wide perfectly conducting metal sections enables large absorbance. It reaches 50 \% provided the filling factor by the two-dimensional system f equals its dimensionless conductivity η=σZ_0/2, where Z_0 is the free-space impedance. The absorbance is further raised to 100 \% if the periodic structure is placed above a perfectly conducting electromagnetic reflector, and provided f=2η. Surprisingly, the optimal distance between two-dimensional system and reflector may fall well below the quarter of incident wavelength λ_0/4, which was assumed as conventional absorption enhancement condition in optics. For low filling factors f≪1, large dielectric constants of the substrate, and grating periods comparable with λ_0, the optimal distance to reflector tends to zero. Above the critical values of the grating geometrical parameters, the absorbance maximum ceases to exist. The critical behavior manifests as a large-amplitude resonance in 'dirty' two-dimensional system with purely real conductivity, while enhancement of carrier momentum relaxation time lowers the resonant peak. Such resonance mimics the plasmonic one, but does not rely on high electron mobility.
ER -