fixedlayer.mx3

/*
Test of Slonczewski torque implementation
Mykola Dvornik
*/

randomSeed := 1234567

setsolver(4)

randSeed(randomSeed)

Nx := 64
Ny := 32
Nz := 16

sX := 128e-9
sY := 64e-9
sZ := 32e-9

setgridsize(Nx, Ny, Nz)
setcellsize(sX/Nx, sY/Ny, sZ/Nz)

Msat = 800e3
Aex = 13e-12

m = randommagseed(randomSeed)

alpha_v := 0.01
alpha = alpha_v
lambda = 1
Pol = 0.5669
epsilonprime = 0.02
DisableZhangLiTorque = true
gamma_v := 2.211e5 / mu0
gammaLL = gamma_v

Jtot := -0.008 // total current in amps
carea := sX * sY
jc := Jtot / carea
print("Current density is: ", jc)

J = vector(0, 0, jc)

grainSize := 4e-9 // m

maxRegion := 255
ext_makegrains(grainSize, maxRegion, randomSeed)

for i := 0; i < maxRegion; i++ {
	FixedLayer.SetRegion(i, vector(randNorm(), randNorm(), randNorm()))
}

print(STtorque.average())
print(torque.average())

save(m)
save(fixedlayer)

TOL := 1e-10

// testing against oommf 2.0a0
// It turnes out that volume averaging with avf2odt does not normalize by the number of cells in z direction
// Hence Nz below

// # ODT 1.0
// ## Desc: Data from vector field file fixedlayer-eprime0.02-Oxs_SpinXferEvolve-evolve-Spin_torque-000000000-0000000.ovf
// ## Active volume: (0,0,0) x (1.28e-07,6.4e-08,3.2e-08)
// ## Cell size: 2e-09 x 2e-09 x 2e-09
// ## Cells in active volume: 32768
// #
// # Table Start
// # Title: Average across active volume
// # Columns:\
// #        M_x                  M_y                  M_z
// #   Units:\
// #       rad/s                rad/s                rad/s
//   585292335.751551    -193932305.309290    -669142900.930218

stt1_v := 585292335.751551 / gamma_v / Nz
stt2_v := -193932305.309290 / gamma_v / Nz
stt3_v := -669142900.930218 / gamma_v / Nz

print(stt1_v, stt2_v, stt3_v)

expectv("STtorque", STtorque.average(), vector(stt1_v, stt2_v, stt3_v), TOL)