#!/usr/bin/env python
# coding: utf-8

# # Domain wall - skyrmion conversion

# In[4]:


import oommfc as oc
import discretisedfield as df
get_ipython().run_line_magic('matplotlib', 'inline')


# In[5]:


A = 15e-12
alpha = 0.3
Ms = 5.8e5
D = 3e-3
K1 = 0.5e6
u = (0, 0, 1)


# In[6]:


system = oc.System(name="conversion")


# In[7]:


system.hamiltonian = oc.Exchange(A=A) + oc.DMI(D=D, crystalclass="Cnv") + oc.UniaxialAnisotropy(K1=K1, u=u)


# In[8]:


system.dynamics = oc.Precession(gamma=2.211e5) + oc.Damping(alpha=alpha)


# In[9]:


p1 = (0, 0, 0)
p2 = (150e-9, 50e-9, 2e-9)
cell = (2e-9, 2e-9, 2e-9)
mesh = oc.Mesh(p1=p1, p2=p2, cell=cell)


# In[10]:


def Ms_fun(pos):
    x, y, z = pos
    if x < 50e-9 and (y < 15e-9 or y > 35e-9):
        return 0
    else:
        return Ms
    
def m_init(pos):
    x, y, z = pos
    if 30e-9 < x < 40e-9:
        return (0.1, 0.1, -1)
    else:
        return (0.1, 0.1, 1)


# In[11]:


system.m = df.Field(mesh, value=m_init, norm=Ms_fun)


# In[12]:


system.m.z.plot_plane(z=0);


# In[13]:


md = oc.MinDriver()
md.drive(system)


# In[14]:


system.m.z.plot_plane(z=0);


# In[15]:


ux = 402.35  # velocity in x direction
beta = 0.5  # non-adiabatic STT parameter

system.dynamics += oc.STT(u=(ux, 0, 0), beta=beta)


# In[16]:


td = oc.TimeDriver()
td.drive(system, t=0.2e-9, n=200)


# In[17]:


system.m.z.plot_plane(z=0);