Encountering difficulties in extracting meaningful insights

[MustakAA]

Hi sir, Take my sincere appreciation for the outstanding work oommf embedded with python. I find myself encountering difficulties in extracting meaningful insights and conclusions. Currently I am working on Current induced domain wall motion for different materials. I used both Zhang-li and Slonczewski term. My problems are:

a) Not completely understand about parameters details that take Zhang-li and Slonczewski term.

b) How can I draw plot: domain wall position vs time or domain wall velocity vs time? Actually I didn't find any column in output data table that is related domain wall position

c) Is it possible to draw plot like: Current density vs domain wall position or Current density vs mobility?

Thank you for your understanding, and I look forward to your help on this matter.

Best regards Mustak Ahamed

[samjrholt]

Hi @MustakAA,

a) The Zhang-Li and Slonczewski terms are crucial in simulating current-induced domain wall motion. In brief, the Zhang-Li term accounts for non-adiabatic spin torque, while the Slonczewski term represents spin-transfer torque. We recommend looking at the literature for further information.

b) To plot domain wall position vs. time or velocity vs. time, you'll need to track the domain wall's position at each simulation step. This is not directly available in the output data and requires additional processing to calculation the domain wall position.

c) This again might need custom data processing based on your simulation outputs.

[MustakAA]

Thank you @samjrholt for your nice reply. Yes. I can track the domain wall's position at each time step by using slider. But I need an idea how can I track the domain wall's position over time value. I need each data point of the domain wall for each step. I need to save all the points. If possible, could you recommend specific literature or provide guidance to clearly understand these Zhang-li and Slonczewski term for ubermag purposes.

[samjrholt]

@MustakAA you can use micromagneticdata to examine the data at each timestep (https://ubermag.github.io/documentation/notebooks/micromagneticdata/documentation.html) . You need to to come up with a methodology to find the position of the domain wall based on the magnetisation field. Then you can plot this quantity vs time.

S. Zhang and Z. Li, Roles of Nonequilibrium Conduction Electrons on the Magnetization Dynamics of Ferromagnets, Physical Review Letters 93, 127204 (2004), online at http://link.aps.org/doi/10.1103/PhysRevLett.93.127204

J. Xiao, A. Zangwill, and M. D. Stiles, ``Boltzmann test of Slonczewski's theory of spin-transfer torque,'' Phys. Rev. B, 70, 172405 (pages 4) (2004)

[MustakAA]

@samjrholt I am reaching out to you to discuss another challenge that has come up in my work, and I believe your insights will be instrumental in finding a solution. How can I pin the Domain wall at different positions using triangular notches? Is it possible in ubermag?