CONDENSED MATTER
Lateral plasmonic superlattice in strongly dissipative regime
I. V. Gorbenko,
V. Yu. Kachorovskii Ioffe Institute, St. Petersburg, 194021 Russia
Abstract:
We study transmission of terahertz radiation through lateral plasmonic superlattice with a unit cell consisting of two regions with different plasma wave velocities,
$s_1$ and
$s_2$ (
$s_1 > s_2$). We generalize theory, developed earlier for resonant case, to the non-resonant regime, assuming that the scattering rate,
$\gamma$, is large compared to fundamental gate-tunable frequencies
$\omega_{1,2}$ of plasma oscillations in both regions. We describe evolution of transmission coefficient,
$\mathcal{T},$ with increasing of radiation frequency, identify several dissipation regimes, construct general diagram describing all these regimes, and find corresponding analytical expressions for
$\mathcal{T}.$ Most importantly,
$\mathcal{T}$ sharply depends on the gate voltages, which control velocities
${{s}_{{1,2}}}$, and on frequency. In particular, for
${{\omega }_{2}} \ll {{\omega }_{1}}$ transmission
$\mathcal{T}$ strongly varies on very small frequency scale,
$\delta \omega \ll \gamma$, determined by the Maxwell relaxation,
$\delta \omega \sim \omega_1^2/\gamma$, so that the superlattice shows very high responsivity within the narrow frequency interval. Unexpected appearance of a narrow peak deep in the non-resonant regime is a universal phenomenon and can also be observed in a number of other photoelectric effects.
Received: 17.10.2024
Revised: 02.06.2025
Accepted: 03.06.2025
DOI:
10.31857/S0370274X25070094
Fulltext:
PDF file (333 kB)
First page:
PDF file