Electromagnetic evanescent field associated with surface acoustic wave: Response of metallic thin films

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Kawada, Takuya, Yamamoto, Kei, Kawaguchi, Masashi, Matsumoto, Hiroki, Hisatomi, Ryusuke, Kohno, Hiroshi, Maekawa, Sadamichi, Hayashi, Masamitsu
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914415080636416
author Kawada, Takuya
Yamamoto, Kei
Kawaguchi, Masashi
Matsumoto, Hiroki
Hisatomi, Ryusuke
Kohno, Hiroshi
Maekawa, Sadamichi
Hayashi, Masamitsu
author_facet Kawada, Takuya
Yamamoto, Kei
Kawaguchi, Masashi
Matsumoto, Hiroki
Hisatomi, Ryusuke
Kohno, Hiroshi
Maekawa, Sadamichi
Hayashi, Masamitsu
contents Surface acoustic waves (SAWs), coherent vibrational modes localized at solid surfaces, have been employed to manipulate and detect electronic and magnetic states in condensed-matter systems via strain. SAWs are commonly excited in a piezoelectric material, often the substrate. In such systems, SAWs not only generate strain but also electric field at the surface. Conventional analysis of the electric field accompanying the SAW invokes the electrostatic approximation, which may fall short in fully capturing its essential characteristics by neglecting the effect of the magnetic field. Here we study the electric and magnetic fields associated with SAWs without introducing the electrostatic approximation. The plane wave solution takes the form of an evanescent field that decays along the surface normal with a phase velocity equal to the speed of sound. If a metallic film is placed on the piezoelectric substrate, a time- and space-varying electric field permeates into the film with a decay length along the film normal defined by the skin depth and the SAW wavelength. For films with high conductivity, the phase of the electric field varies along the film normal. The emergence of the evanescent field is a direct consequence of dropping the electrostatic approximation, providing a simple but critical physical interpretation of the SAW-induced electromagnetic field.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13436
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electromagnetic evanescent field associated with surface acoustic wave: Response of metallic thin films
Kawada, Takuya
Yamamoto, Kei
Kawaguchi, Masashi
Matsumoto, Hiroki
Hisatomi, Ryusuke
Kohno, Hiroshi
Maekawa, Sadamichi
Hayashi, Masamitsu
Mesoscale and Nanoscale Physics
Surface acoustic waves (SAWs), coherent vibrational modes localized at solid surfaces, have been employed to manipulate and detect electronic and magnetic states in condensed-matter systems via strain. SAWs are commonly excited in a piezoelectric material, often the substrate. In such systems, SAWs not only generate strain but also electric field at the surface. Conventional analysis of the electric field accompanying the SAW invokes the electrostatic approximation, which may fall short in fully capturing its essential characteristics by neglecting the effect of the magnetic field. Here we study the electric and magnetic fields associated with SAWs without introducing the electrostatic approximation. The plane wave solution takes the form of an evanescent field that decays along the surface normal with a phase velocity equal to the speed of sound. If a metallic film is placed on the piezoelectric substrate, a time- and space-varying electric field permeates into the film with a decay length along the film normal defined by the skin depth and the SAW wavelength. For films with high conductivity, the phase of the electric field varies along the film normal. The emergence of the evanescent field is a direct consequence of dropping the electrostatic approximation, providing a simple but critical physical interpretation of the SAW-induced electromagnetic field.
title Electromagnetic evanescent field associated with surface acoustic wave: Response of metallic thin films
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2412.13436