KAIST Finds Clue to 'Dream Memory' Realization Through Orbital Magnetism Control

The possibility of controlling magnetism using "orbital exchange interaction" instead of the electron's spin property in semiconductors has been presented. Orbital exchange interaction refers to the phenomenon where the orbits (orbitals) formed as electrons revolve around the atomic nucleus influence each other, thereby controlling the direction and properties of the magnet. Applying this theory is expected to help reduce heat generation in smartphones and laptops and bring the realization of "dream memory" with low power consumption closer to reality.

On March 16, KAIST announced that a joint research team led by Professor Kyungjin Kim of the Department of Physics at KAIST and Professor Kyunghwan Kim of the Department of Physics at Yonsei University has established a new theoretical framework, for the first time in the world, that enables free control of magnetism using the electron's "orbital exchange interaction."

(From left) Dr. Keunhee Lee, Professor Kyungjin Kim, and Professor Kyunghwan Kim of Yonsei University. KAIST

Until now, next-generation memory research has focused on the electron's "spin." Spin refers to the property generated by an electron spinning like a small top, which stores information depending on its direction of rotation. At the same time, the electron also performs orbital motion, revolving around the atomic nucleus along a path called an "orbital."

Through their research, the joint team theoretically identified the principle that the orbital energy of electrons generated when current flows directly interacts with the orbitals of the magnetic material, transmitting information. This confirmed that the properties of magnets can be changed more efficiently compared to conventional spin-based methods.

The most significant achievement of the research is the revelation that current can not only change the direction of a magnet but also control the fundamental physical properties of the magnet itself, such as its directional preference and rotational characteristics.

In particular, the joint research team confirmed that control effects using orbitals are stronger than those based on spin. This points to the possibility of opening a new era of "orbital-based electronic devices," where orbitals, rather than spin, play a central role in semiconductor components.

The research team also presented a method for measuring these effects in actual experiments, which is expected to enhance the potential for future industrial applications.

It is also worth noting that this principle can be applied to "altermagnetic" materials, which have recently attracted attention in academia.

Altermagnetism refers to a new form of magnetic material in which the spins of electrons within atoms are regularly arranged in different directions. Although they may not appear magnetic externally, they have a significant impact on electron movement.

Thanks to these properties, altermagnetic materials are attracting attention as promising candidates for precise control of electron states, memory control, and the development of high-speed, low-power semiconductor devices. In the same context, the new theoretical framework established by the joint research team is expected to provide a strong theoretical foundation for the development of next-generation logic and memory devices.

Dr. Geunhee Lee of KAIST stated, "This research demonstrates that it is not always necessary to rely solely on spin to control magnetism with electric current. The new perspective of understanding and controlling magnetism through the electron's orbital motion will serve as a significant milestone in the development of next-generation ultra-fast, low-power memory."

This research was conducted with Dr. Geunhee Lee of KAIST as the first author, and Professor Kyunghwan Kim of Yonsei University and Professor Kyungjin Kim of KAIST as co-corresponding authors. The research paper was published in the international journal "Nature Communications" on February 2 of the previous month.

This content was produced with the assistance of AI translation services.