Speaker
Description
The Smith-Purcell effect has various applications, from noninvasive diagnostics of relativistic electron beams and generation of powerful THz radiation to micro- and nano-electronics. In the latter field, the instruments and devices operate with small currents, down to single electrons. Being sensitive to electrons passing near periodic structures, Smith-Purcell radiation (SPR) can be used to create current sensors. In the 1990s, infrared Smith-Purcell radiation was used to measure the mean free path of hot electrons in GaAd/AIGaAs heterostructures [1]. Periodic gratings with different period lengths, of the order of hundreds of nanometers, were organized on the top layer of the heterostructure. A similar structure was used in [2] to measure the velocity distribution of two-dimensional electron gas in heterostructures. The success of both experiments confirms the prospects of using Smith-Purcell effect in electronics. Interestingly, research into interaction of two-dimensional electron flows with surface periodic arrays continues today, but in other applications such as flash-memory [3], and so on.
In microelectronics, electrons move essentially inside material, contrary to the traditional applications of SPR. The motion inside material affects SPR, since dielectric properties of the material screen the field of the beam and affect the interference of radiation, leading to a change in SPR dispersion relation. Earlier, the SPR in medium was considered in recent papers of Schepkovich et al. [4] and Potylitsyn et al. [5], but only for the electrons moving beyond medium.
In this report we present the results of our studies of the SPR generated by electrons moving in a medium. Based on previously developed methods [6-9], we have obtained expressions for the characteristics of the radiation, including the field, the spectral and angular energy distributions. We discuss the role of frequency dispersion of the medium properties: new, impossible out of medium, diffraction orders of SPR and special features of SPR in the regions of anomalous dispersion. We also review new prospects for the application of SPR in microelectronics.
The study was supported by a grant from the Russian Science Foundation No. 24-72-00150.
[1] C. Kiener, C. Wirner, W. Boxleitner, E. Gornik, G. Bohm, G. Weimann, Investigation of the mean free path of hot electrons in GaAs/AIGaAs heterostructures, Semiconductor Science and Technology 9, 193 (1994).
[2] E. Gornik, W. Boxleitner, V. Robkopf, M. Hauser, C. Wirner, G. Weimann, Smith-Purcell effect in GaAs/AIGaAs heterostructures, Superlattices and Microstructures 15, 399 (1994).
[3] Y. Xiang, C. Wang, C. Liu, T. Wang, Y. Jiang, Y. Wang, S. Wang, and P. Zhou, Subnanosecond flash memory enabled by 2D-enhanced hot-carrier injection, Nature 641, 90 (2025).
[4] D. Konakhovych, D. Sniezek, O. Warmusz, D. S. Black, Z. Zhao, R. J. England, A. Szczepkowicz,
Internal Smith-Purcell radiation and its interplay with Cherenkov diffraction radiation in silicon -- a combined time and frequency domain numerical study, arXiv: 2105.07682 (2021).
[5] A.P. Potylitsyn, Smith–Purcell Radiation in Dielectric and the Anomalous Doppler Effect, JETP Letters 121, 691 (2025).
[6] A.A. Tishchenko, D.Yu. Sergeeva, Near-field resonances in photon emission via interaction of electrons with coupled nanoparticles, Phys. Rev. B 100, 235421 (2019).
[7] D.Yu. Sergeeva, A.A. Tishchenko, Enhanced Smith-Purcell radiation based on quasibound states in the continuum in dimers aligned in a chain, Phys. Rev. B 108, 155435 (2023).
[8] D. I. Garaev, D. Yu. Sergeeva, A. A. Tishchenko, Theory of Smith-Purcell radiation from a 2D array of small noninteracting particles, Phys. Rev. B 103, 075403 (2021).
[9] D. Yu. Sergeeva, A. S. Aryshev, A. A. Tishchenko, K. E. Popov, N. Terunuma, J. Urakawa, THz Smith–Purcell and grating transition radiation from metasurface: experiment and theory, Optics Letters 46, 544 (2021).