Characteristics of THz surface waves propagating through metal and composite graphene nanofilms
V.V. Gerasimov1'2*. A.K. Nikitin3, V.D. Kukotenko1, V.S. Vanda12, A.G. Lemzyakov1'4, A.I. Ivanov5, I.V. Antonova5, I.A. Azarov25
1-Budker Institute of Nuclear Physics of SB RAS, 11, Lavrentiev prospect, 630090, Novosibirsk, Russia 2- Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia 3- Scientific and Technological Centre of Unique Instrum. of RAS, 15, Butlerova str., 117342, Moscow, Russia 4- Synchrotron Radiation Facility SKIF, 1, pr. Nikolsky, 630559 Kol'tsovo, Russia 5- Rzhanov Institute of Semiconductor Physics SB RAS, 13 Lavrentiev Aven., Novosibirsk 630090, Russia
* v.v.gerasimov@inp.nsk.su
With the general trend towards miniaturization and integration of devices, THz range technologies occupy a unique position for combining electronic and photonic components within a single integrated circuit [1]. In recent years, promising results have been demonstrated in this field [2], and with the advancement of wireless communication technologies, the THz range has become a key one in solving the spectrum shortage problem and meeting the increasing demands for data volume and transmission speed in 6G systems and beyond [3]. THz technologies promise significant improvements in the energy efficiency of data transmission compared to the existing 5G systems [4]. Of particular interest in this context is the research on plasmonic materials, which enable creation of compact antennas with high element density due to the subwavelength localization of surface plasmons [5].
Surface plasmon polaritons (SPPs), or simply "surface plasmons", are a complex of coupled oscillations of a surface electromagnetic wave and a wave of charges propagating along the interface between a conductor and a dielectric [6]. The field of the surface electromagnetic wave exponentially decays on both sides of the interface, and its penetration depth into the dielectric (most often air) can be of the order of or even less than the wavelength of the bulk radiation to generate SPPs, which allows one to overcome the diffraction limit.
Metals, semiconductors, graphene, and other materials can be used as a conductor for propagation of SPPs. The choice of a particular material for plasmonics is determined by its efficiency in the generation of SPPs, the distance of SPP propagation along the conductor, availability and ease of fabrication, and the possibility of control of its optical properties with external influences (temperature and electric or magnetic fields).
The talk will review results, including recent ones, on the characteristics of SPPs propagating over metal-dielectric and composite graphene surfaces using THz radiation from the Novosibirsk free electron laser in the range 0.8-6 THz. The results include an analysis of the influence of roughness, conductivity, and manufacturing technology of conductive materials on energy losses and field localization of SPPs at the conductor surface.
The work was done at the shared research facility Siberian Center for Synchrotron and Terahertz Radiation on the basis of the Novosibirsk Free Electron Laser at Budker Institute of Nuclear Physics SB RAS. The authors thank the core facilities VTAN (Novosibirsk State University) for the access to the experimental equipment.
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