Ask for help about adding interfacial dmi function.

[bowenphys]

• When i test：

using JuMag
using Printf
using NPZ

JuMag.cuda_using_double(true)

mesh =  CubicMeshGPU(nx=150, ny=50, nz=1, pbc="xy")

function m0_fun(i,j,k, dx, dy, dz)
  r2 = (i-70)^2 + (j-25)^2
  if r2 < 10^2
    return (0.01, 0, -1)
  end
  return (0,0,1)
end

function relax_system()
  sim = Sim(mesh, driver="SD", name="skx")
  set_mu_s(sim, mu_s_1)
  init_m0(sim, m0_fun)
 
  J = 50 * k_B
  add_exch(sim, J, name="exch")
  add_dmi(sim, 0.5*J, name="dmi", type = "bulk")

  Hz = 0.2 * J / mu_s_1
  add_zeeman(sim, (0,0,Hz))

  relax(sim, maxsteps=2000, stopping_dmdt=0.01)

  save_vtk(sim, "skx", fields=["exch", "dmi"])

end

relax_system()

• i get a error：ERROR: MethodError: no method matching add_dmi(::JuMag.AtomicSimGPU{Float64}, ::Float64; type::String)

Closest candidates are:
  add_dmi(::JuMag.AtomicSimGPU, ::Real; name) got unsupported keyword argument "type"
   @ JuMag C:\Users\11302\.julia\packages\JuMag\yH1A2\src\atomistic\sim.jl:212
  add_dmi(::JuMag.AbstractSim, ::Real; name, type)
   @ JuMag C:\Users\11302\.julia\packages\JuMag\yH1A2\src\add_field.jl:263
  add_dmi(::JuMag.AbstractSim, ::Any) got unsupported keyword argument "type"
   @ JuMag C:\Users\11302\.julia\packages\JuMag\yH1A2\src\add_field.jl:297
  ...

Stacktrace:
 [1] kwerr(::@NamedTuple{type::String}, ::Function, ::JuMag.AtomicSimGPU{Float64}, ::Float64)
   @ Base .\error.jl:165
 [2] relax_system()
   @ Main c:\Users\11302\Desktop\Code\Julia\JuMag\test.jl:24
 [3] top-level scope
   @ c:\Users\11302\Desktop\Code\Julia\JuMag\test.jl:35

it is also error for add_dmi(sim, D, type="interfacial") add_dmi(sim, D, type="bulk")
my julia version is 1.10rc.

[ww1g11]

I checked the source codes and found that the atomistic part only support the bulk dmi.

function relax_system()
  sim = Sim(mesh, driver="SD", name="skx")
  set_mu_s(sim, mu_s_1)
  init_m0(sim, m0_fun)
 
  J = 50 * k_B
  add_exch(sim, J, name="exch")
  add_dmi(sim, 0.5*J, name="dmi")

  Hz = 0.2 * J / mu_s_1
  add_zeeman(sim, (0,0,Hz))

  relax(sim, maxsteps=2000, stopping_dmdt=0.1)

  save_vtk(sim, "skx", fields=["exch", "dmi"])
end

A possible solution for the interfacial dmi is to use the micromagnetic code by mapping the parameters from atomistic model to micromagnetic model using A=J/2a and D=D_0^2/a^2.

We will tidy up JuMag code soon and add the interfacial dmi for atomistic part then.