- Physicists develop a new model to better control an array of square-shaped nanomagnets.
- The technique could be useful in high capacity data storage, and micro- and nanosurgery.
Over the last couple of decades, there has been a keen interest in researching nanoscale elements. It’s because of their possible applications in micro- and nanosurgery, high capacity data storage, and spintronics, especially at the external field frequencies similar to the eigenfrequencies.
Under specific scenarios, the magnetization of micro and nanoscale materials demonstrates the vortex distribution. Due to the competition between demagnetization and exchange of energies, a highly inhomogeneous magnetized region is formed at the vortex core center.
To develop ultrahigh-capacity data storage equipment, you need to have the highest possible density of materials in an array made up of separate nanomagnets. The closer these materials are, the higher the magnetic interactions between them.
Rather than one resonance line, multiple magnetic resonance lines exist when square-nanomagnets are placed close to each other. The multiple magnetic resonance lines from different vibrational modes across individual nanomangnets get aligned with other vibrational modes of the complete array system.
The interaction between magnetic elements gets weaker with the increase in distance, and thus vibrational mode frequencies of magnetization weakly differ from the resonant frequency of the core motion in each element.
Precession of gyroscope | Wikimedia
The nanometric square material’s magnetization isn’t fixed; it travels in a helical motion. This is due to the spin of electrons — also referred as degree of freedom — that follows a precession motion centered on the middle part of the nanometric square material.
New Model To Control Nanomagnets
Researchers can count on 2D arrays of square nanomagnets to analyze the magnetization of such material. Recently, Russian physicists at the Kirensky Institute of Physics developed a new model to better control such nanomagnet arrays. They have considered all parameters responsible for magnetic interaction between each nanomagnet.
Magnetization structure for a part of the array of square elements | Credit: Springer
Unlike previous researchers that used several geometries of a given nanomagnet, this study analyzes different combinations of polarities and chiralities of the closest elements in the array. It takes following factors into account-
- Magnetostatic interaction between the core magnetic moments.
- Non-cylindrical symmetry of the potential, where the core is situated as a quasiparticle.
- Quadrupole term for measuring magnetostatic interaction energy for nanometric square elements.
Reference: Springer | doi:10.1140/epjb/e2018-90006-0
A significant interplay between elements could help control the magnetization mode — polarity and chirality–in arrays of tightly packed magnetic materials. It could open the possibilities of governing the mode of an entire set of elements united by a single vibrational state.
Bottom line: you can’t ignore the interplay of magnetic moments while developing devices based on huge arrays of nanosized materials.