コード例 #1
0
ファイル: rod.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-10, atol=1e-14)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((1,1,1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 2e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #2
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ファイル: main.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-6, atol=1e-6)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)
    #sim.set_m((0,0.1,1))
    #sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1.3e-3)
    sim.add(dmi)

    anis = UniaxialAnisotropy(-3.25e4, axis=(0, 0, 1))
    sim.add(anis)

    zeeman = Zeeman((0, 0, 6.014576e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13,
              stopping_dmdt=0.5,
              max_steps=5000,
              save_m_steps=None,
              save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #3
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ファイル: test_prb88_184422.py プロジェクト: fangohr/fidimag
def run_fidimag(mesh):

    mu0 = 4 * np.pi * 1e-7

    Ms = 8.6e5
    A = 16e-12
    D = -3.6e-3
    K = 510e3

    sim = Sim(mesh)

    sim.set_tols(rtol=1e-10, atol=1e-10)

    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.do_precession = False

    sim.set_m((0, 0, 1))

    sim.add(UniformExchange(A))
    sim.add(DMI(D, dmi_type='interfacial'))
    sim.add(UniaxialAnisotropy(K, axis=(0, 0, 1)))

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    m = sim.spin
    return m.copy()
コード例 #4
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ファイル: test_stt_dw.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    # Only relaxation
    sim = Sim(mesh, name='relax')

    # Simulation parameters
    sim.set_tols(rtol=1e-8, atol=1e-10)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    # The initial state passed as a function
    sim.set_m(init_m)
    # sim.set_m(np.load('m0.npy'))

    # Energies
    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    anis = UniaxialAnisotropy(5e4)
    sim.add(anis)

    # dmi = DMI(D=8e-4)
    # sim.add(dmi)

    # Start relaxation and save the state in m0.npy
    sim.relax(dt=1e-14,
              stopping_dmdt=0.00001,
              max_steps=5000,
              save_m_steps=None,
              save_vtk_steps=None)

    np.save('m0.npy', sim.spin)
コード例 #5
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ファイル: main.py プロジェクト: logicabrity/fidimag
def relax_system(mesh):

    # Only relaxation
    sim = Sim(mesh, name='relax')

    # Simulation parameters
    sim.driver.set_tols(rtol=1e-8, atol=1e-10)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    # The initial state passed as a function
    sim.set_m(init_m)
    # sim.set_m(np.load('m0.npy'))

    # Energies
    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    anis = UniaxialAnisotropy(5e4)
    sim.add(anis)

    # Start relaxation and save the state in m0.npy
    sim.relax(dt=1e-14, stopping_dmdt=0.00001, max_steps=5000,
              save_m_steps=None, save_vtk_steps=None)

    np.save('m0.npy', sim.spin)
コード例 #6
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def run_fidimag(mesh):

    mu0 = 4 * np.pi * 1e-7

    Ms = 8.6e5
    A = 16e-12
    D = -3.6e-3
    K = 510e3

    sim = Sim(mesh)

    sim.set_tols(rtol=1e-10, atol=1e-10)

    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.do_precession = False

    sim.set_m((0, 0, 1))

    sim.add(UniformExchange(A))
    sim.add(DMI(D, type='interfacial'))
    sim.add(UniaxialAnisotropy(K, axis=(0, 0, 1)))

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    m = sim.spin
    return m.copy()
コード例 #7
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ファイル: test_dw_dmi.py プロジェクト: fangohr/fidimag
def test_dw_dmi(mesh=mesh, do_plot=False):

    Ms = 8.0e5
    sim = Sim(mesh, name='relax')

    sim.set_m(m_init_dw)

    sim.set_tols(rtol=1e-8, atol=1e-12)
    sim.Ms = Ms
    sim.alpha = 0.5
    sim.do_precession = False

    A = 1.3e-11
    D = 4e-4
    Kx = 8e4
    Kp = -6e5

    sim.add(UniformExchange(A))
    sim.add(DMI(D))
    sim.add(UniaxialAnisotropy(Kx, axis=[1, 0, 0], name='Kx'))

    sim.relax(stopping_dmdt=0.01)

    xs = np.array([p[0] for p in mesh.coordinates])
    mx, my, mz = analytical(xs, A=A, D=D, K=Kx)
    mxyz = sim.spin.copy()
    mxyz = mxyz.reshape(-1, 3)

    assert max(abs(mxyz[:, 0] - mx)) < 0.002
    assert max(abs(mxyz[:, 1] - my)) < 0.002
    assert max(abs(mxyz[:, 2] - mz)) < 0.0006

    if do_plot:

        save_plot(mxyz, mx, my, mz)
コード例 #8
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def relax_system(mesh):

    sim = Sim(mesh, name="relax")

    sim.driver.set_tols(rtol=1e-10, atol=1e-14)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 2e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000, save_m_steps=None, save_vtk_steps=50)

    np.save("m0.npy", sim.spin)
コード例 #9
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ファイル: main.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-6, atol=1e-6)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)
    #sim.set_m((0,0.1,1))
    #sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1.3e-3)
    sim.add(dmi)

    anis = UniaxialAnisotropy(-3.25e4, axis=(0, 0, 1))
    sim.add(anis)

    zeeman = Zeeman((0, 0, 6.014576e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=0.5, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #10
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ファイル: sinlge_cube.py プロジェクト: owlas/fidimag
def compute_field():

    mesh = CuboidMesh(nx=1, ny=1, nz=1, dx=2.0, dy=2.0, dz=2.0, unit_length=1e-9, periodicity=(True, True, False))

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-10, atol=1e-14)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((0,0,1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag(pbc_2d=True)
    sim.add(demag)
    field=demag.compute_field()
    print field

    np.save('m0.npy', sim.spin)
コード例 #11
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def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.driver.set_tols(rtol=1e-6, atol=1e-6)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)

    exch = UniformExchange(A=1.3e-11)
    sim.add(exch)

    dmi = DMI(D=-4e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 4e5))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=1e-2,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #12
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ファイル: single_cube.py プロジェクト: writergirish/fidimag
def compute_field():

    mesh = CuboidMesh(nx=1,
                      ny=1,
                      nz=1,
                      dx=2.0,
                      dy=2.0,
                      dz=2.0,
                      unit_length=1e-9,
                      periodicity=(True, True, False))

    sim = Sim(mesh, name='relax')

    sim.driver.set_tols(rtol=1e-10, atol=1e-14)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((0, 0, 1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag(pbc_2d=True)
    sim.add(demag)
    field = demag.compute_field()
    print(field)

    np.save('m0.npy', sim.spin)
コード例 #13
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ファイル: main.py プロジェクト: writergirish/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.driver.set_tols(rtol=1e-10, atol=1e-10)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.0e5
    sim.do_precession = False

    sim.set_m((1, 0.25, 0.1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag()
    sim.add(demag)

    sim.relax(dt=1e-13,
              stopping_dmdt=0.01,
              max_steps=5000,
              save_m_steps=100,
              save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #14
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ファイル: main.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-6, atol=1e-6)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)

    exch = UniformExchange(A=1.3e-11)
    sim.add(exch)

    dmi = DMI(D=-4e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 4e5))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13,
              stopping_dmdt=1e-2,
              save_m_steps=None,
              save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #15
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ファイル: test_2dpbc_cube.py プロジェクト: fangohr/fidimag
def test_compute_field():
    """In an infinite film, we expect the demag tensor to be (0, 0, -1), and thus the
    magnetisation, if aligned in 0, 0, 1 direction, to create a demag field pointing
    with equal strength in the opposite direction.
    """

    mesh = CuboidMesh(nx=1,
                      ny=1,
                      nz=1,
                      dx=2.0,
                      dy=2.0,
                      dz=2.0,
                      unit_length=1e-9,
                      periodicity=(True, True, False))

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-10, atol=1e-14)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((0, 0, 1))

    demag = Demag(pbc_2d=True)
    sim.add(demag)
    field = demag.compute_field()
    print((1 + field[2] / 8.6e5))
    assert abs(1 + field[2] / 8.6e5) < 1e-10
コード例 #16
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def test_dw_dmi(mesh=mesh, do_plot=False):

    Ms = 8.0e5
    sim = Sim(mesh, name='relax')

    sim.set_m(m_init_dw)

    sim.driver.set_tols(rtol=1e-8, atol=1e-12)
    sim.Ms = Ms
    sim.alpha = 0.5
    sim.do_precession = False

    A = 1.3e-11
    D = 4e-4
    Kx = 8e4
    Kp = -6e5

    sim.add(UniformExchange(A))
    sim.add(DMI(D))
    sim.add(UniaxialAnisotropy(Kx, axis=[1, 0, 0], name='Kx'))

    sim.driver.relax(stopping_dmdt=0.01)

    xs = np.array([p[0] for p in mesh.coordinates])
    mx, my, mz = analytical(xs, A=A, D=D, K=Kx)
    mxyz = sim.spin.copy()
    mxyz = mxyz.reshape(-1, 3)

    assert max(abs(mxyz[:, 0] - mx)) < 0.002
    assert max(abs(mxyz[:, 1] - my)) < 0.002
    assert max(abs(mxyz[:, 2] - mz)) < 0.0006

    if do_plot:

        save_plot(mxyz, mx, my, mz)
コード例 #17
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def setup_domain_wall_cobalt(node_count=NODE_COUNT, A=A_Co, Ms=Ms_Co, K1=K1_Co, length=LENGTH, do_precession=True, unit_length=UNIT_LENGTH):
    a = length / node_count  # cell size
    mesh = CuboidMesh(dx=a, dy=a, dz=a, nx=node_count, ny=1, nz=1, unit_length=unit_length)
    sim = Sim(mesh, "dw_cobalt")
    sim.Ms = Ms
    sim.set_m(lambda r: initial_m(r, length))
    sim.do_precession = do_precession
    sim.add(UniformExchange(A))
    sim.add(UniaxialAnisotropy(K1, (0, 0, 1)))
    sim.pins = lambda r: 1 if (r[0] < a or r[0] > LENGTH - a) else 0
    return sim
コード例 #18
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def setup_domain_wall_cobalt(node_count=NODE_COUNT, A=A_Co, Ms=Ms_Co, K1=K1_Co, length=LENGTH, do_precession=True, unit_length=UNIT_LENGTH):
    a = length / node_count  # cell size
    mesh = CuboidMesh(dx=a, dy=a, dz=a, nx=node_count, ny=1, nz=1, unit_length=unit_length)
    sim = Sim(mesh, "dw_cobalt")
    sim.Ms = Ms
    sim.set_m(lambda r: initial_m(r, length))
    sim.do_precession = do_precession
    sim.add(UniformExchange(A))
    sim.add(UniaxialAnisotropy(K1, (0, 0, 1)))
    sim.pins = lambda r: 1 if (r[0] < a or r[0] > LENGTH - a) else 0
    return sim
コード例 #19
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ファイル: main.py プロジェクト: fangohr/fidimag
def relax_system_only_exchange(mesh):

    sim = Sim(mesh, name='relax_exchange_only')

    sim.set_tols(rtol=1e-6, atol=1e-6)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m_BP)

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    sim.relax(dt=1e-13, stopping_dmdt=0.5, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #20
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ファイル: main.py プロジェクト: writergirish/fidimag
def relax_system_only_exchange(mesh):

    sim = Sim(mesh, name='relax_exchange_only')

    sim.driver.set_tols(rtol=1e-6, atol=1e-6)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m_BP)

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    sim.relax(dt=1e-13, stopping_dmdt=0.5, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #21
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def test_compute_field():
    """In an infinite film, we expect the demag tensor to be (0, 0, -1), and thus the
    magnetisation, if aligned in 0, 0, 1 direction, to create a demag field pointing
    with equal strength in the opposite direction.
    """

    mesh = CuboidMesh(nx=1, ny=1, nz=1, dx=2.0, dy=2.0, dz=2.0,
                      unit_length=1e-9, periodicity=(True, True, False))

    sim = Sim(mesh, name='relax')

    sim.driver.set_tols(rtol=1e-10, atol=1e-14)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((0, 0, 1))

    demag = Demag(pbc_2d=True)
    sim.add(demag)
    field = demag.compute_field()
    print((1 + field[2] / 8.6e5))
    assert abs(1 + field[2] / 8.6e5) < 1e-10
コード例 #22
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ファイル: main.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-10, atol=1e-10)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.0e5
    sim.do_precession = False

    sim.set_m((1, 0.25, 0.1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag()
    sim.add(demag)

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000,
              save_m_steps=100, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)
コード例 #23
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                      nz=nz,
                      dx=dx,
                      dy=dy,
                      dz=dz,
                      unit_length=1e-9,
                      pbc=(True, True, False))

# Initiate Fidimag simulation ---------------------------------------------
sim = Sim(mesh, name=args.sim_name)

# sim.driver.set_tols(rtol=1e-10, atol=1e-14)
sim.driver.alpha = args.alpha
# sim.driver.gamma = 2.211e5

if args.no_precession:
    sim.do_precession = False

# Material parameters -----------------------------------------------------

sim.Ms = args.Ms

exch = UniformExchange(A=args.A)
sim.add(exch)

dmi = DMI(D=(args.D * 1e-3), type='interfacial')
sim.add(dmi)

if args.B:
    zeeman = Zeeman((0, 0, args.B / mu0))
    sim.add(zeeman, save_field=True)
コード例 #24
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ファイル: skyrmion_relax.py プロジェクト: fangohr/fidimag
    x, y = pos[0] - radius, pos[1] - radius

    if x ** 2 + y ** 2 < radius ** 2:
        return (0, 0, 1)
    else:
        return (0, 0, -1)

# Prepare simulation

# We define the cylinder with the Magnetisation function
sim = Sim(mesh, name='skyrmion')
sim.Ms = cylinder

# To get a faster relaxation, we tune the LLG equation parameters
sim.do_precession = False
sim.alpha = 0.5

# Initial magnetisation:
sim.set_m(init_m)

# Energies:

# Exchange
sim.add(UniformExchange(A=A))

# Bulk DMI
sim.add(DMI(D=D))

# Relax the system
sim.relax(dt=1e-12, stopping_dmdt=0.0001, max_steps=5000,