# Topological magnetoelectric effects in microwave far-field radiation

## Abstract

Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

- Authors:

- Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

- Publication Date:

- OSTI Identifier:
- 22597760

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTENNAS; ELECTRICAL PROPERTIES; ELECTROMAGNETIC FIELDS; ELECTROMAGNETISM; FERRITE; FERRITES; HELICITY; MAGNETIC FIELDS; MAGNETIC PROPERTIES; MAXWELL EQUATIONS; MICROWAVE RADIATION; ORBITAL ANGULAR MOMENTUM; RESONATORS; SPIN; SYMMETRY BREAKING; TOPOLOGY; TORSION; VECTORS

### Citation Formats

```
Berezin, M., Kamenetskii, E. O., and Shavit, R.
```*Topological magnetoelectric effects in microwave far-field radiation*. United States: N. p., 2016.
Web. doi:10.1063/1.4958866.

```
Berezin, M., Kamenetskii, E. O., & Shavit, R.
```*Topological magnetoelectric effects in microwave far-field radiation*. United States. doi:10.1063/1.4958866.

```
Berezin, M., Kamenetskii, E. O., and Shavit, R. Thu .
"Topological magnetoelectric effects in microwave far-field radiation". United States.
doi:10.1063/1.4958866.
```

```
@article{osti_22597760,
```

title = {Topological magnetoelectric effects in microwave far-field radiation},

author = {Berezin, M. and Kamenetskii, E. O. and Shavit, R.},

abstractNote = {Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.},

doi = {10.1063/1.4958866},

journal = {Journal of Applied Physics},

number = 3,

volume = 120,

place = {United States},

year = {Thu Jul 21 00:00:00 EDT 2016},

month = {Thu Jul 21 00:00:00 EDT 2016}

}