Chapter 19
Magnetoelectric Near Fields
Eugene Kamenetskii
Abstract Similar to electromagnetic (EM) phenomena, described by Maxwell equations, physics of magnetoelectric (ME) phenomena deals with the fundamental problems of the relationship between electric and magnetic fields. The different nature
of these two notions is especially evident in dynamic regimes. Analyzing the EM
phenomena inside the ME material, the question arises: What kind of the near fields,
originated from a sample of such a material, can be measured? Observation of the
ME states requires an experimental technique characterized by a violation of spatial
and temporal inversion symmetries in a subwavelength region. This presumes the
existence of specific near fields. Recently, such field structures, called ME fields,
were found as the near fields of a quasi-2D subwavelength-size ferrite disk with
magnetic-dipolar-mode (MDM) oscillations. The key physical characteristics that
determine the configurations of the ME near fields are the spin and orbital angular
momenta of the quantum states of the MDM spectra. This leads to the appearance of
subwavelength power-flow vortices. By virtue of unique topology, the ME quantum
fluctuations in vacuum are different from virtual EM photons. While preserving the
ME properties, one observes strong enhancing the near-field intensity. The main
purpose of this chapter is to review and analyze the studies of the ME fields. We
consider the near-field topological singularities originated from the MDM ferritedisk particle. These topological features can be transmitted to various types of
nonmagnetic material structures.
19.1 Introduction
Symmetry principles play an important role in the laws of nature. Maxwell added
an electric displacement current to put into a symmetrical form the equations which
couple together the electric and magnetic fields. The dual symmetry between electric
E. Kamenetskii (B)
Microwave Magnetic Laboratoty, Ben Gurion University of the Negev, Beersheba, Israel
e-mail: kmntsk@bgu.ac.il
© Springer Nature Switzerland AG 2021
E. Kamenetskii (ed.), Chirality, Magnetism and Magnetoelectricity,
Topics in Applied Physics 138,
https://doi.org/10.1007/978-3-030-62844-4_19
523
Magnetoelectric Near Fields
Eugene Kamenetskii
Abstract Similar to electromagnetic (EM) phenomena, described by Maxwell equations, physics of magnetoelectric (ME) phenomena deals with the fundamental problems of the relationship between electric and magnetic fields. The different nature
of these two notions is especially evident in dynamic regimes. Analyzing the EM
phenomena inside the ME material, the question arises: What kind of the near fields,
originated from a sample of such a material, can be measured? Observation of the
ME states requires an experimental technique characterized by a violation of spatial
and temporal inversion symmetries in a subwavelength region. This presumes the
existence of specific near fields. Recently, such field structures, called ME fields,
were found as the near fields of a quasi-2D subwavelength-size ferrite disk with
magnetic-dipolar-mode (MDM) oscillations. The key physical characteristics that
determine the configurations of the ME near fields are the spin and orbital angular
momenta of the quantum states of the MDM spectra. This leads to the appearance of
subwavelength power-flow vortices. By virtue of unique topology, the ME quantum
fluctuations in vacuum are different from virtual EM photons. While preserving the
ME properties, one observes strong enhancing the near-field intensity. The main
purpose of this chapter is to review and analyze the studies of the ME fields. We
consider the near-field topological singularities originated from the MDM ferritedisk particle. These topological features can be transmitted to various types of
nonmagnetic material structures.
19.1 Introduction
Symmetry principles play an important role in the laws of nature. Maxwell added
an electric displacement current to put into a symmetrical form the equations which
couple together the electric and magnetic fields. The dual symmetry between electric
E. Kamenetskii (B)
Microwave Magnetic Laboratoty, Ben Gurion University of the Negev, Beersheba, Israel
e-mail: kmntsk@bgu.ac.il
© Springer Nature Switzerland AG 2021
E. Kamenetskii (ed.), Chirality, Magnetism and Magnetoelectricity,
Topics in Applied Physics 138,
https://doi.org/10.1007/978-3-030-62844-4_19
523