コード例 #1
0
def excite_system(mesh):

    sim = Sim(mesh, name='dyn', driver='sllg')
    sim.set_options(dt=1e-14, gamma=const.gamma, k_B=const.k_B)
    sim.alpha = 0.1
    sim.mu_s = const.mu_s_1
    sim.T = temperature_gradient

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

    J = 50.0 * const.k_B
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.5 * J
    dmi = DMI(D)
    sim.add(dmi)

    Hz = 0.2 * J / const.mu_s_1
    zeeman = Zeeman([0, 0, Hz])
    sim.add(zeeman)

    dt = 2e-14 * 50  # 1e-12
    ts = np.linspace(0, 1000 * dt, 501)
    for t in ts:
        sim.run_until(t)
        sim.save_vtk()
        sim.save_m()
        print 'sim t=%g' % t
コード例 #2
0
ファイル: skx.py プロジェクト: fangohr/fidimag
def relax_system(mesh):

    sim=Sim(mesh,name='relax')
    sim.set_options(rtol=1e-12,atol=1e-14)
    sim.do_precession = False
    sim.alpha = 0.5
    sim.gamma = 1.0
    sim.mu_s = 1.0

    sim.set_m(init_m)

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0,0e-3,2e-2],name='H')
    sim.add(zeeman)

    sim.relax(dt=2.0, stopping_dmdt=1e-8, max_steps=10000, save_m_steps=None, save_vtk_steps=100)

    np.save('m0.npy',sim.spin)
コード例 #3
0
def excite_system(mesh):

    sim = Sim(mesh, name='dyn', driver='sllg')
    sim.set_options(dt=1e-14, gamma=const.gamma, k_B=const.k_B)
    sim.driver.alpha = 0.1
    sim.mu_s = const.mu_s_1
    sim.T = temperature_gradient

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

    J = 50.0 * const.k_B
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.5 * J
    dmi = DMI(D)
    sim.add(dmi)

    Hz = 0.2 * J / const.mu_s_1
    zeeman = Zeeman([0, 0, Hz])
    sim.add(zeeman)

    dt = 2e-14 * 50  # 1e-12
    ts = np.linspace(0, 1000 * dt, 501)
    for t in ts:
        sim.run_until(t)
        sim.save_vtk()
        sim.save_m()
        print 'sim t=%g' % t
コード例 #4
0
ファイル: dyn.py プロジェクト: ww1g11/fidimag
def relax_system(mesh, Hy=0):

    sim = Sim(mesh, name="relax")
    sim.set_options(rtol=1e-10, atol=1e-12)
    sim.alpha = 0.5
    sim.gamma = 1.0
    sim.mu_s = 1.0

    sim.do_precession = False

    sim.set_m(init_m)
    # sim.set_m(random_m)
    # sim.set_m(np.load('m_10000.npy'))

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0, Hy, 2e-2], name="H")
    sim.add(zeeman)

    sim.relax(dt=2.0, stopping_dmdt=1e-8, max_steps=10000, save_m_steps=100, save_vtk_steps=50)

    np.save("m0.npy", sim.spin)
コード例 #5
0
ファイル: dyn.py プロジェクト: ww1g11/fidimag
def excite_system(mesh, Hy=0):

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

    sim.set_options(rtol=1e-10, atol=1e-12)
    sim.alpha = 0.04
    sim.gamma = 1.0
    sim.mu_s = 1.0

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

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0, Hy, 2e-2], name="H")
    sim.add(zeeman)

    hx = TimeZeeman([0, 0, 1e-5], sinc_fun, name="h")
    sim.add(hx, save_field=True)

    dt = 5
    steps = 2001
    for i in range(steps):

        sim.run_until(i * dt)
コード例 #6
0
ファイル: skx.py プロジェクト: takluyver/fidimag
def relax_system(mesh):

    sim = Sim(mesh, name='relax')
    sim.set_options(rtol=1e-12, atol=1e-14)
    sim.do_procession = False
    sim.alpha = 0.5
    sim.gamma = 1.0
    sim.mu_s = 1.0

    sim.set_m(init_m)

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0, 0e-3, 2e-2], name='H')
    sim.add(zeeman)

    sim.relax(dt=2.0,
              stopping_dmdt=1e-8,
              max_steps=10000,
              save_m_steps=None,
              save_vtk_steps=100)

    np.save('m0.npy', sim.spin)
コード例 #7
0
ファイル: phase.py プロジェクト: takluyver/fidimag
def excite_system(T=0.1, H=0.15):

    mesh = CuboidMesh(nx=28 * 3, ny=16 * 5, nz=1, pbc='2d')

    sim = Sim(mesh, name='dyn', driver='sllg')
    sim.set_options(dt=1e-14, gamma=const.gamma, k_B=const.k_B)
    sim.alpha = 0.1
    sim.mu_s = const.mu_s_1

    sim.set_m(random_m)

    J = 50 * const.k_B
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.5 * J
    dmi = DMI(D)
    sim.add(dmi)

    Hz = H * J / const.mu_s_1
    zeeman = Zeeman([0, 0, Hz])
    sim.add(zeeman)

    sim.T = J / const.k_B * T

    ts = np.linspace(0, 5e-11, 51)
    for t in ts:
        sim.run_until(t)
        # sim.save_vtk()

    np.save('m.npy', sim.spin)
    plot_m(mesh, 'm.npy', comp='z')
コード例 #8
0
def excite_system(mesh, Hy=0):

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

    sim.set_options(rtol=1e-10,atol=1e-12)
    sim.driver.alpha = 0.04
    sim.driver.gamma = 1.0
    sim.mu_s = 1.0

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

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0,Hy,2e-2],name='H')
    sim.add(zeeman)

    hx = TimeZeeman([0,0,1e-5], sinc_fun, name='h')
    sim.add(hx, save_field=True)


    dt = 5
    steps = 2001
    for i in range(steps):

        sim.run_until(i*dt)
コード例 #9
0
def relax_system(mesh, Hy=0):

    sim=Sim(mesh,name='relax')
    sim.set_options(rtol=1e-10,atol=1e-12)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 1.0
    sim.mu_s = 1.0

    sim.do_precession = False

    sim.set_m(init_m)
    #sim.set_m(random_m)
    #sim.set_m(np.load('m_10000.npy'))

    J = 1.0
    exch = UniformExchange(J)
    sim.add(exch)

    D = 0.18
    dmi = DMI(D)
    sim.add(dmi)

    zeeman = Zeeman([0,Hy,2e-2],name='H')
    sim.add(zeeman)

    sim.relax(dt=2.0, stopping_dmdt=1e-8, max_steps=10000, save_m_steps=100, save_vtk_steps=50)

    np.save('m0.npy',sim.spin)
コード例 #10
0
def test_sim_single_spin_sllg(do_plot=False):

    mesh = CuboidMesh(nx=1, ny=1, nz=1)

    sim = Sim(mesh, name='spin', driver='sllg')

    alpha = 0.1
    gamma = 2.21e5

    sim.set_options(dt=5e-15, gamma=gamma)

    sim.alpha = alpha
    sim.mu_s = 1.0

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

    H0 = 1e5
    sim.add(Zeeman((0, 0, H0)))

    ts = np.linspace(0, 1e-10, 101)

    mx = []
    my = []
    mz = []
    real_ts = []
    for t in ts:
        sim.run_until(t)
        real_ts.append(sim.t)
        print(sim.t, abs(sim.spin_length()[0] - 1))
        mx.append(sim.spin[0])
        my.append(sim.spin[1])
        mz.append(sim.spin[2])

    mz = np.array(mz)

    a_mx, a_my, a_mz = single_spin(alpha, gamma, H0, ts)

    if do_plot:
        plot(real_ts,
             mx,
             my,
             mz,
             a_mx,
             a_my,
             a_mz,
             name='spin_sllg.pdf',
             title='integrating a spin')

    print(("Max Deviation = {0}".format(np.max(np.abs(mz - a_mz)))))

    assert np.max(np.abs(mz - a_mz)) < 1e-8
コード例 #11
0
ファイル: test_single_spin.py プロジェクト: ww1g11/fidimag
def relax_system(rtol=1e-10, atol=1e-12):
    """numerical solution"""
    mesh = CuboidMesh(nx=1, ny=1, nz=1)
    sim = Sim(mesh, name="relax")
    sim.set_options(rtol=rtol, atol=atol)
    sim.alpha = 0.5
    sim.gamma = 2.21e5
    sim.mu_s = 1.0

    sim.set_m((1.0, 0, 0))

    sim.add(Zeeman((0, 0, 1e5)))

    ts = np.linspace(0, 1e-9, 1001)

    for t in ts:
        sim.run_until(t)
コード例 #12
0
ファイル: test_single_spin.py プロジェクト: takluyver/fidimag
def relax_system(rtol=1e-10, atol=1e-12):
    """numerical solution"""
    mesh = CuboidMesh(nx=1, ny=1, nz=1)
    sim = Sim(mesh, name='relax')
    sim.set_options(rtol=rtol, atol=atol)
    sim.alpha = 0.5
    sim.gamma = 2.21e5
    sim.mu_s = 1.0

    sim.set_m((1.0, 0, 0))

    sim.add(Zeeman((0, 0, 1e5)))

    ts = np.linspace(0, 1e-9, 1001)

    for t in ts:
        sim.run_until(t)
コード例 #13
0
ファイル: test_llg_atomistic.py プロジェクト: fangohr/fidimag
def test_sim_single_spin_sllg(do_plot=False):

    mesh = CuboidMesh(nx=1, ny=1, nz=1)

    sim = Sim(mesh, name='spin', driver='sllg')

    alpha = 0.1
    gamma = 2.21e5

    sim.set_options(dt=5e-15, gamma=gamma)

    sim.alpha = alpha
    sim.mu_s = 1.0

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

    H0 = 1e5
    sim.add(Zeeman((0, 0, H0)))

    ts = np.linspace(0, 1e-10, 101)

    mx = []
    my = []
    mz = []
    real_ts = []
    for t in ts:
        sim.run_until(t)
        real_ts.append(sim.t)
        print(sim.t, abs(sim.spin_length()[0] - 1))
        mx.append(sim.spin[0])
        my.append(sim.spin[1])
        mz.append(sim.spin[2])

    mz = np.array(mz)

    a_mx, a_my, a_mz = single_spin(alpha, gamma, H0, ts)

    if do_plot:
        plot(real_ts, mx, my, mz, a_mx, a_my, a_mz, name='spin_sllg.pdf', title='integrating a spin')

    print(("Max Deviation = {0}".format(
        np.max(np.abs(mz - a_mz)))))

    assert np.max(np.abs(mz - a_mz)) < 1e-8