Periodic Reporting for period 1 - Standard EF (The research of spin orbit torques in perpendicular magnetic anisotropy systems.)
Reporting period: 2016-10-01 to 2018-09-30
These effects are intriguing for its possible high efficient manipulation and stabilization of spin structures for application memory applications. However, in order to manipulate and maximize these effects first we must understand the underlying mechanisms. The project has focused on understanding the underlying physics of DMI and SOT by studying these effects in various systems. By fully understanding the effects and being able to manipulate the effects in a manner to fully maximize the efficiency. This would lead to possible technologies for designing an ultra-efficient memory devices.
Along with the research on DMI we have studied the SOT in various systems to get a grasp on the underlying mechanism. Here we have also measured the SOT by different methods to validate whether there could be a standard for quantifying SOTs (Figure 2). Here, we have found out in determining SOT the existence of a domain wall makes it complex to compare the values with that measured in a mono-domain system. On the basis of these results, the SOT was evaluated in various material systems. We have measured the magnetic material thickness dependence and the temperature dependence. The temperature dependence revealed that the skew scattering mechanism of the spin Hall effect was dominant for the Pt based material stacks we observed. Also we have looked at possible correlations between the DMI and SOT in a material system where the DMI changes sign with the composition of the magnetic layer.
As a result of this research a number of papers were published and the results were disseminated at national and international conferences.