Spintronics is a field of research that explores the use of electron spins instead of electric charges for information processing and storage. The ability to control spin currents, which are flows of electron spins, is vital for realizing spintronics devices. However, the behavior of spin currents under temperature changes is still poorly understood, hindering their practical applications.
In their study, published in the journal Nature Communications, the researchers used a newly developed technique called the spin-torque ferromagnetic resonance spectroscopy to measure the DMI and the spin current temperature dependence of various thin films.
The DMI is a magnetic interaction between neighboring spins that arises from the lack of inversion symmetry in a crystal. It can be either positive or negative, depending on the material and its structure.
The researchers found that the spin current was strongly affected by the sign and the strength of the DMI. In particular, materials with a positive DMI showed a decrease in the spin current with increasing temperature, while those with a negative DMI showed an increase. This behavior could be explained by the temperature-dependent fluctuations of the magnetic moments, which are enhanced by the DMI.
The research team also demonstrated that the DMI could be effectively controlled by applying an external magnetic field. By tuning the magnetic field, they could reverse the sign of the DMI and change the temperature dependence of the spin current.
These findings provide a deeper understanding of the relationship between the magnetic properties of a material and the behavior of spin currents, and pave the way for designing new spintronics devices that can operate stably at different temperatures.
The study opens up exciting possibilities for the future of spintronics, enabling the development of novel devices such as spin-based logic circuits, magnetic sensors, and high-density magnetic memory with improved performance and energy efficiency.
