Ejemplo n.º 1
0
def excite_system_D(mesh, Hx=2000):

    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4 * np.pi * 1e-7
    G = A / (mu0 * Ms**2)

    Nx = 0
    Ny = 0.4
    Nz = 0.6

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

    sim.set_tols(rtol=1e-8, atol=1e-8)
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.alpha = 0.005

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

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

    demag = SimpleDemag(Nx=Nx, Ny=Ny, Nz=Nz)
    sim.add(demag)

    hx = Zeeman((Hx, 0, 0), name='Hx')
    sim.add(hx, save_field=True)

    ts = np.linspace(0, 5e-9, 101)
    for t in ts:
        print 'time', t
        sim.run_until(t)
Ejemplo n.º 2
0
def excite_system_D(mesh, Hx=2000):

    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4*np.pi*1e-7
    G = A/(mu0*Ms**2)

    Nx = 0
    Ny = 0.4
    Nz = 0.6

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

    sim.driver.set_tols(rtol=1e-8,atol=1e-8)
    sim.driver.gamma = 2.211e5
    sim.Ms = Ms
    sim.driver.alpha = 0.005

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

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

    demag = SimpleDemag(Nx=Nx, Ny=Ny, Nz=Nz)
    sim.add(demag)

    hx = Zeeman((Hx,0,0), name='Hx')
    sim.add(hx, save_field=True)

    ts = np.linspace(0, 5e-9, 101)
    for t in ts:
        print 'time', t
        sim.run_until(t)
Ejemplo n.º 3
0
def relax_system(mesh):
    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4*np.pi*1e-7

    Nx = 0
    Ny = 0.4
    Nz = 0.6

    K = 0.5*(Ny-Nx)*mu0*Ms**2
    Kp = -0.5*(Nz-Ny)*mu0*Ms**2

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

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

    sim.set_m(init_dw)

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

    kx = UniaxialAnisotropy(K, axis=(1,0,0))
    sim.add(kx)

    kp = UniaxialAnisotropy(Kp, axis=(0,0,1))
    sim.add(kp)

    sim.relax(dt=1e-14, stopping_dmdt=0.01, max_steps=5000, save_m_steps=None, save_vtk_steps=None)

    np.save('m0.npy',sim.spin)
Ejemplo n.º 4
0
def excite_system_K(mesh, Hx=2000):

    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4*np.pi*1e-7
    G = A/(mu0*Ms**2)

    Nx = 0
    Ny = 0.4
    Nz = 0.6

    K = 0.5*(Ny-Nx)*mu0*Ms**2
    Kp = -0.5*(Nz-Ny)*mu0*Ms**2

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

    sim.driver.set_tols(rtol=1e-8,atol=1e-8)
    sim.driver.gamma = 2.211e5
    sim.Ms = Ms
    sim.driver.alpha = 0.005

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

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

    kx = UniaxialAnisotropy(K, axis=(1,0,0))
    sim.add(kx)

    kp = UniaxialAnisotropy(Kp, axis=(0,0,1))
    sim.add(kp)

    hx = Zeeman((Hx,0,0), name='Hx')
    sim.add(hx, save_field=True)


    ts = np.linspace(0, 5e-9, 501)
    for t in ts:
        print 'time', t
        sim.run_until(t)
Ejemplo n.º 5
0
def excite_system_K(mesh, Hx=2000):

    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4 * np.pi * 1e-7
    G = A / (mu0 * Ms**2)

    Nx = 0
    Ny = 0.4
    Nz = 0.6

    K = 0.5 * (Ny - Nx) * mu0 * Ms**2
    Kp = -0.5 * (Nz - Ny) * mu0 * Ms**2

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

    sim.set_tols(rtol=1e-8, atol=1e-8)
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.alpha = 0.005

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

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

    kx = UniaxialAnisotropy(K, axis=(1, 0, 0))
    sim.add(kx)

    kp = UniaxialAnisotropy(Kp, axis=(0, 0, 1))
    sim.add(kp)

    hx = Zeeman((Hx, 0, 0), name='Hx')
    sim.add(hx, save_field=True)

    ts = np.linspace(0, 5e-9, 501)
    for t in ts:
        print 'time', t
        sim.run_until(t)
Ejemplo n.º 6
0
def relax_system(mesh):
    A = 1.3e-11
    Ms = 8.6e5
    mu0 = 4 * np.pi * 1e-7

    Nx = 0
    Ny = 0.4
    Nz = 0.6

    K = 0.5 * (Ny - Nx) * mu0 * Ms**2
    Kp = -0.5 * (Nz - Ny) * mu0 * Ms**2

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

    sim.set_tols(rtol=1e-8, atol=1e-8)
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.alpha = 0.5
    sim.do_procession = False

    sim.set_m(init_dw)

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

    kx = UniaxialAnisotropy(K, axis=(1, 0, 0))
    sim.add(kx)

    kp = UniaxialAnisotropy(Kp, axis=(0, 0, 1))
    sim.add(kp)

    sim.relax(dt=1e-14,
              stopping_dmdt=0.01,
              max_steps=5000,
              save_m_steps=None,
              save_vtk_steps=None)

    np.save('m0.npy', sim.spin)