Slonczewski’s Theory of Spin Transfer Torque

[王kyne]

Hello all，
I am currently working on a spin transfer torque (STT) model simulation, but I am not entirely clear on the physical meaning of certain parameters, such as Lambda and EpsilonPrime. I found the formula for STT on the official website, but it appears quite different from the form of the STT equation I was previously familiar with. Can these two expressions be converted into one another, or do they correspond to differephysical frameworks? Are there any references or literature that could help clarify this?  

[Jiaxuan Chen]

Hello all，

Recently, I have been doing STT model simulation, but I do not understand the physical meaning of parameters, such as Lambda and EpsilonPrime. The relevant information I have consulted is shown in the figure. What is the relationship between ϵ and ϵ' here, and what is their relationship with the damping-like torque and the field-like torque? What is the value of ϵ' based on?