Ejemplo n.º 1
0
def get_test_impurity_model(norb=2, ntau=1000, beta=10.0):
    """ Function that generates a random impurity model for testing """

    from pytriqs.operators import c, c_dag, Operator, dagger

    from pyed.OperatorUtils import fundamental_operators_from_gf_struct
    from pyed.OperatorUtils import symmetrize_quartic_tensor
    from pyed.OperatorUtils import get_quadratic_operator
    from pyed.OperatorUtils import operator_from_quartic_tensor

    orb_idxs = list(np.arange(norb))
    spin_idxs = ['up', 'do']
    gf_struct = [[spin_idx, orb_idxs] for spin_idx in spin_idxs]

    # -- Random Hamiltonian

    fundamental_operators = fundamental_operators_from_gf_struct(gf_struct)

    N = len(fundamental_operators)
    t_OO = np.random.random((N, N)) + 1.j * np.random.random((N, N))
    t_OO = 0.5 * (t_OO + np.conj(t_OO.T))

    #print 't_OO.real =\n', t_OO.real
    #print 't_OO.imag =\n', t_OO.imag

    U_OOOO = np.random.random((N, N, N, N)) + 1.j * np.random.random(
        (N, N, N, N))
    U_OOOO = symmetrize_quartic_tensor(U_OOOO, conjugation=True)

    #print 'gf_struct =', gf_struct
    #print 'fundamental_operators = ', fundamental_operators

    H_loc = get_quadratic_operator(t_OO, fundamental_operators) + \
        operator_from_quartic_tensor(U_OOOO, fundamental_operators)

    #print 'H_loc =', H_loc

    from pytriqs.gf import MeshImTime, BlockGf

    mesh = MeshImTime(beta, 'Fermion', ntau)
    Delta_tau = BlockGf(mesh=mesh, gf_struct=gf_struct)

    for block_name, delta_tau in Delta_tau:
        delta_tau.data[:] = -0.5

    return gf_struct, Delta_tau, H_loc
Ejemplo n.º 2
0
                     indices=[1])

    g_iwn = GfImFreq(name='$g$',
                     beta=beta,
                     statistic='Fermion',
                     n_points=10,
                     indices=[1])

    ed.set_g2_tau(g_tau, c(up, 0), c_dag(up, 0))
    ed.set_g2_iwn(g_iwn, c(up, 0), c_dag(up, 0))

    # ------------------------------------------------------------------
    # -- Two particle Green's functions

    ntau = 20
    imtime = MeshImTime(beta, 'Fermion', ntau)
    prodmesh = MeshProduct(imtime, imtime, imtime)

    g40_tau = Gf(name='g40_tau', mesh=prodmesh, target_shape=[1, 1, 1, 1])
    g4_tau = Gf(name='g4_tau', mesh=prodmesh, target_shape=[1, 1, 1, 1])

    ed.set_g40_tau(g40_tau, g_tau)
    ed.set_g4_tau(g4_tau, c(up, 0), c_dag(up, 0), c(up, 0), c_dag(up, 0))

    # ------------------------------------------------------------------
    # -- Two particle Green's functions (equal times)

    prodmesh = MeshProduct(imtime, imtime)
    g3pp_tau = Gf(name='g4_tau', mesh=prodmesh, target_shape=[1, 1, 1, 1])
    ed.set_g3_tau(g3pp_tau, c(up, 0), c_dag(up, 0), c(up, 0) * c_dag(up, 0))
Ejemplo n.º 3
0
    beta = 10.0
    U = 2.0
    mu = 1.0
    h = 0.1
    #V = 0.5
    V = 1.0
    epsilon = 2.3

    H = U * n('up', 0) * n('do', 0) + \
        - mu * (n('up', 0) + n('do', 0)) + \
        h * n('up', 0) - h * n('do', 0) + \
        epsilon * (n('up', 1) + n('do', 1)) - epsilon * (n('up', 2) + n('do', 2)) + \
        V * ( c_dag('up', 0) * c('up', 1) + c_dag('up', 1) * c('up', 0) ) + \
        V * ( c_dag('do', 0) * c('do', 1) + c_dag('do', 1) * c('do', 0) ) + \
        V * ( c_dag('up', 0) * c('up', 2) + c_dag('up', 2) * c('up', 0) ) + \
        V * ( c_dag('do', 0) * c('do', 2) + c_dag('do', 2) * c('do', 0) )

    ed = TriqsExactDiagonalization(H, fundamental_operators, beta)

    n_tau = 101
    G_tau_up = Gf(mesh=MeshImTime(beta, 'Fermion', n_tau), target_shape=[])
    G_tau_do = Gf(mesh=MeshImTime(beta, 'Fermion', n_tau), target_shape=[])

    ed.set_g2_tau(G_tau_up, c('up', 0), c_dag('up', 0))
    ed.set_g2_tau(G_tau_do, c('do', 0), c_dag('do', 0))

    with HDFArchive('anderson.pyed.h5', 'w') as Results:
        Results['up'] = G_tau_up
        Results['dn'] = G_tau_do
Ejemplo n.º 4
0
from pytriqs.gf import Gf, MeshImFreq, MeshImTime, iOmega_n, inverse, Fourier, InverseFourier

beta = 10.0

gf_struct = [['0', [0, 1]]]
target_shape = [2, 2]

nw = 48
nt = 3 * nw

S = SolverCore(beta=beta, gf_struct=gf_struct, n_iw=nw, n_tau=nt)

h_int = n('0', 0) * n('0', 1)

wmesh = MeshImFreq(beta=beta, S='Fermion', n_max=nw)
tmesh = MeshImTime(beta=beta, S='Fermion', n_max=nt)

Delta_iw = Gf(mesh=wmesh, target_shape=target_shape)

Ek = np.array([
    [1.00,  0.75],
    [0.75, -1.20],
    ])

E_loc = np.array([
    [0.2, 0.3],
    [0.3, 0.4],
    ])

V = np.array([
    [1.0, 0.25],
Ejemplo n.º 5
0
def make_calc(U=10):

    # ------------------------------------------------------------------
    # -- Hubbard atom with two bath sites, Hamiltonian

    params = dict(
        beta=2.0,
        V1=2.0,
        V2=5.0,
        epsilon1=0.00,
        epsilon2=4.00,
        mu=2.0,
        U=U,
        ntau=40,
        niw=15,
    )

    # ------------------------------------------------------------------

    class Dummy():
        def __init__(self):
            pass

    d = Dummy()  # storage space
    d.params = params

    print '--> Solving SIAM with parameters'
    for key, value in params.items():
        print '%10s = %-10s' % (key, str(value))
        globals()[key] = value  # populate global namespace

    # ------------------------------------------------------------------

    up, do = 0, 1
    docc = c_dag(up, 0) * c(up, 0) * c_dag(do, 0) * c(do, 0)
    nA = c_dag(up, 0) * c(up, 0) + c_dag(do, 0) * c(do, 0)
    nB = c_dag(up, 1) * c(up, 1) + c_dag(do, 1) * c(do, 1)
    nC = c_dag(up, 2) * c(up, 2) + c_dag(do, 2) * c(do, 2)

    d.H = -mu * nA + epsilon1 * nB + epsilon2 * nC + U * docc + \
        V1 * (c_dag(up,0)*c(up,1) + c_dag(up,1)*c(up,0) + \
              c_dag(do,0)*c(do,1) + c_dag(do,1)*c(do,0) ) + \
        V2 * (c_dag(up,0)*c(up,2) + c_dag(up,2)*c(up,0) + \
              c_dag(do,0)*c(do,2) + c_dag(do,2)*c(do,0) )

    # ------------------------------------------------------------------
    # -- Exact diagonalization

    fundamental_operators = [
        c(up, 0), c(do, 0),
        c(up, 1), c(do, 1),
        c(up, 2), c(do, 2)
    ]

    ed = TriqsExactDiagonalization(d.H, fundamental_operators, beta)

    # ------------------------------------------------------------------
    # -- Single-particle Green's functions

    Gopt = dict(beta=beta, statistic='Fermion', indices=[1])
    d.G_tau = GfImTime(name=r'$G(\tau)$', n_points=ntau, **Gopt)
    d.G_iw = GfImFreq(name='$G(i\omega_n)$', n_points=niw, **Gopt)

    ed.set_g2_tau(d.G_tau, c(up, 0), c_dag(up, 0))
    ed.set_g2_iwn(d.G_iw, c(up, 0), c_dag(up, 0))

    # chi2pp = + < c^+_u(\tau^+) c_u(0^+) c^+_d(\tau) c_d(0) >
    #        = - < c^+_u(\tau^+) c^+_d(\tau) c_u(0^+) c_d(0) >

    chi2opt = dict(beta=beta, statistic='Fermion', indices=[1], n_points=ntau)
    d.chi2pp_tau = GfImTime(name=r'$\chi^{(2)}_{PP}(\tau)$', **chi2opt)
    ed.set_g2_tau(d.chi2pp_tau,
                  c_dag(up, 0) * c_dag(do, 0),
                  c(up, 0) * c(do, 0))
    d.chi2pp_tau *= -1.0 * -1.0  # commutation sign and gf sign
    d.chi2pp_iw = g_iw_from_tau(d.chi2pp_tau, niw)

    # chi2ph = < c^+_u(\tau^+) c_u(\tau) c^+_d(0^+) c_d(0) >

    d.chi2ph_tau = GfImTime(name=r'$\chi^{(2)}_{PH}(\tau)$', **chi2opt)
    #d.chi2ph_tau = Gf(name=r'$\chi^{(2)}_{PH}(\tau)$', **chi2opt)
    ed.set_g2_tau(d.chi2ph_tau,
                  c_dag(up, 0) * c(up, 0),
                  c_dag(do, 0) * c(do, 0))
    d.chi2ph_tau *= -1.0  # gf sign
    d.chi2ph_iw = g_iw_from_tau(d.chi2ph_tau, niw)

    # ------------------------------------------------------------------
    # -- Two particle Green's functions

    imtime = MeshImTime(beta, 'Fermion', ntau)
    prodmesh = MeshProduct(imtime, imtime, imtime)
    G2opt = dict(mesh=prodmesh, target_shape=[1, 1, 1, 1])

    d.G02_tau = Gf(name='$G^{(2)}_0(\tau_1, \tau_2, \tau_3)$', **G2opt)
    ed.set_g40_tau(d.G02_tau, d.G_tau)
    d.G02_iw = chi4_iw_from_tau(d.G02_tau, niw)

    d.G2_tau = Gf(name='$G^{(2)}(\tau_1, \tau_2, \tau_3)$', **G2opt)
    ed.set_g4_tau(d.G2_tau, c_dag(up, 0), c(up, 0), c_dag(do, 0), c(do, 0))
    #ed.set_g4_tau(d.G2_tau, c(up,0), c_dag(up,0), c(do,0), c_dag(do,0)) # <cc^+cc^+>
    d.G2_iw = chi4_iw_from_tau(d.G2_tau, niw)

    # -- trying to fix the bug in the fft for w2

    d.G02_iw.data[:] = d.G02_iw.data[:, ::-1, ...].conj()
    d.G2_iw.data[:] = d.G2_iw.data[:, ::-1, ...].conj()

    # ------------------------------------------------------------------
    # -- 3/2-particle Green's functions (equal times)

    prodmesh = MeshProduct(imtime, imtime)
    chi3opt = dict(mesh=prodmesh, target_shape=[1, 1, 1, 1])

    # chi3pp = <c^+_u(\tau) c_u(0^+) c^+_d(\tau') c_d(0) >
    #        = - <c^+_u(\tau) c^+_d(\tau') c_u(0^+) c_d(0) >

    d.chi3pp_tau = Gf(name='$\Chi^{(3)}_{PP}(\tau_1, \tau_2, \tau_3)$',
                      **chi3opt)
    ed.set_g3_tau(d.chi3pp_tau, c_dag(up, 0), c_dag(do, 0),
                  c(up, 0) * c(do, 0))
    d.chi3pp_tau *= -1.0  # from commutation
    d.chi3pp_iw = chi3_iw_from_tau(d.chi3pp_tau, niw)

    # chi3ph = <c^+_u(\tau) c_u(\tau') c^+_d(0^+) c_d(0) >

    d.chi3ph_tau = Gf(name='$\Chi^{(3)}_{PH}(\tau_1, \tau_2, \tau_3)$',
                      **chi3opt)
    ed.set_g3_tau(d.chi3ph_tau, c_dag(up, 0), c(up, 0),
                  c_dag(do, 0) * c(do, 0))
    d.chi3ph_iw = chi3_iw_from_tau(d.chi3ph_tau, niw)

    # ------------------------------------------------------------------
    # -- Store to hdf5

    filename = 'data_ed.h5'
    with HDFArchive(filename, 'w') as res:
        for key, value in d.__dict__.items():
            res[key] = value
Ejemplo n.º 6
0
for tau in g_tau.mesh:
    g_tau[tau] = np.exp(-beta * tau)

for idx, tau in enumerate(g_tau.mesh):

    # comparison does not work at beta since the evaluation g_tau() wraps..
    if idx == len(g_tau.mesh) - 1: break

    #diff_interp = g_tau(tau)[0,0] - g_ref[idx] # FIXME: tau is complex

    diff_interp = g_tau(tau.real)[0, 0] - g_ref[idx]
    diff_dbrack = g_tau[tau][0, 0] - g_ref[idx]

    np.testing.assert_almost_equal(diff_interp, 0.0)
    np.testing.assert_almost_equal(diff_dbrack, 0.0)

# -- three imaginary time gf

imtime = MeshImTime(beta=beta, S='Fermion', n_max=ntau)
g4_tau = Gf(name='g4_tau',
            mesh=MeshProduct(imtime, imtime, imtime),
            indices=[1])

for t1, t2, t3 in g4_tau.mesh:
    g4_tau[t1, t2, t3] = g_tau(t1) * g_tau(t3) - g_tau(t1) * g_tau(t3)

for t1, t2, t3 in g4_tau.mesh:
    val = g4_tau[t1, t2, t3]
    val_ref = g_tau(t1) * g_tau(t3) - g_tau(t1) * g_tau(t3)
    np.testing.assert_array_almost_equal(val, val_ref)
Ejemplo n.º 7
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        debug_H.append(H)

    # ------------------------------------------------------------------

    Delta_iw = BlockGf(mesh=iw_mesh, gf_struct=gf_struct)
    H_loc_block = []

    for block, g0_iw in G0_iw:

        tail, err = g0_iw.fit_hermitian_tail()
        H_loc = tail[2]
        Delta_iw[block] << inverse(g0_iw) + H_loc - iOmega_n

        H_loc_block.append(H_loc)

    tau_mesh = MeshImTime(beta, 'Fermion', n_tau)
    Delta_tau = BlockGf(mesh=tau_mesh, gf_struct=gf_struct)
    Delta_tau << Fourier(Delta_iw)

    # ------------------------------------------------------------------

    # ------------------------------------------------------------------
    exit()

    from pytriqs.plot.mpl_interface import oplot, oploti, oplotr, plt
    subp = [3, 1, 1]
    plt.subplot(*subp)
    subp[-1] += 1
    oplot(G0_iw)
    plt.subplot(*subp)
    subp[-1] += 1
Ejemplo n.º 8
0
def test_two_particle_greens_function():

    # ------------------------------------------------------------------
    # -- Hubbard atom with two bath sites, Hamiltonian
    
    beta = 2.0
    V1 = 2.0
    V2 = 5.0
    epsilon1 = 0.00
    epsilon2 = 4.00
    mu = 2.0
    U = 0.0

    up, do = 0, 1
    docc = c_dag(up,0) * c(up,0) * c_dag(do,0) * c(do,0)
    nA = c_dag(up,0) * c(up,0) + c_dag(do,0) * c(do,0)
    nB = c_dag(up,1) * c(up,1) + c_dag(do,1) * c(do,1)
    nC = c_dag(up,2) * c(up,2) + c_dag(do,2) * c(do,2)

    H = -mu * nA + epsilon1 * nB + epsilon2 * nC + U * docc + \
        V1 * (c_dag(up,0)*c(up,1) + c_dag(up,1)*c(up,0) + \
              c_dag(do,0)*c(do,1) + c_dag(do,1)*c(do,0) ) + \
        V2 * (c_dag(up,0)*c(up,2) + c_dag(up,2)*c(up,0) + \
              c_dag(do,0)*c(do,2) + c_dag(do,2)*c(do,0) )
    
    # ------------------------------------------------------------------
    # -- Exact diagonalization

    fundamental_operators = [
        c(up,0), c(do,0), c(up,1), c(do,1), c(up,2), c(do,2)]
    
    ed = TriqsExactDiagonalization(H, fundamental_operators, beta)

    # ------------------------------------------------------------------
    # -- single particle Green's functions

    g_tau = GfImTime(name=r'$g$', beta=beta,
                     statistic='Fermion', n_points=100,
                     target_shape=(1,1))
    
    ed.set_g2_tau(g_tau[0, 0], c(up,0), c_dag(up,0))
    
    # ------------------------------------------------------------------
    # -- Two particle Green's functions

    ntau = 10
    imtime = MeshImTime(beta, 'Fermion', ntau)
    prodmesh = MeshProduct(imtime, imtime, imtime)

    g40_tau = Gf(name='g40_tau', mesh=prodmesh, target_shape=(1,1,1,1))
    g4_tau = Gf(name='g4_tau', mesh=prodmesh, target_shape=(1,1,1,1))

    ed.set_g40_tau_matrix(g40_tau, g_tau)
    ed.set_g4_tau(g4_tau[0, 0, 0, 0], c(up,0), c_dag(up,0), c(up,0), c_dag(up,0))

    # ------------------------------------------------------------------
    # -- compare

    zero_outer_planes_and_equal_times(g4_tau)
    zero_outer_planes_and_equal_times(g40_tau)
    np.testing.assert_array_almost_equal(g4_tau.data, g40_tau.data)
Ejemplo n.º 9
0
def make_calc(beta=2.0, h_field=0.0):

    # ------------------------------------------------------------------
    # -- Hubbard atom with two bath sites, Hamiltonian

    p = ParameterCollection(
        beta=beta,
        V1=2.0,
        V2=5.0,
        epsilon1=0.10,
        epsilon2=3.00,
        h_field=h_field,
        mu=0.0,
        U=5.0,
        ntau=800,
        niw=15,
    )

    # ------------------------------------------------------------------

    print '--> Solving SIAM with parameters'
    print p

    # ------------------------------------------------------------------

    up, do = 'up', 'dn'
    docc = c_dag(up, 0) * c(up, 0) * c_dag(do, 0) * c(do, 0)
    mA = c_dag(up, 0) * c(up, 0) - c_dag(do, 0) * c(do, 0)

    nA = c_dag(up, 0) * c(up, 0) + c_dag(do, 0) * c(do, 0)
    nB = c_dag(up, 1) * c(up, 1) + c_dag(do, 1) * c(do, 1)
    nC = c_dag(up, 2) * c(up, 2) + c_dag(do, 2) * c(do, 2)

    p.H = -p.mu * nA + p.U * docc + p.h_field * mA + \
        p.epsilon1 * nB + p.epsilon2 * nC + \
        p.V1 * (c_dag(up,0)*c(up,1) + c_dag(up,1)*c(up,0) + \
              c_dag(do,0)*c(do,1) + c_dag(do,1)*c(do,0) ) + \
        p.V2 * (c_dag(up,0)*c(up,2) + c_dag(up,2)*c(up,0) + \
              c_dag(do,0)*c(do,2) + c_dag(do,2)*c(do,0) )

    # ------------------------------------------------------------------

    fundamental_operators = [
        c(up, 0), c(do, 0),
        c(up, 1), c(do, 1),
        c(up, 2), c(do, 2)
    ]

    ed = TriqsExactDiagonalization(p.H, fundamental_operators, p.beta)

    g_tau = GfImTime(beta=beta, statistic='Fermion', n_points=400, indices=[0])
    g_iw = GfImFreq(beta=beta, statistic='Fermion', n_points=10, indices=[0])

    p.G_tau = BlockGf(name_list=[up, do],
                      block_list=[g_tau] * 2,
                      make_copies=True)
    p.G_iw = BlockGf(name_list=[up, do],
                     block_list=[g_iw] * 2,
                     make_copies=True)

    ed.set_g2_tau(p.G_tau[up][0, 0], c(up, 0), c_dag(up, 0))
    ed.set_g2_tau(p.G_tau[do][0, 0], c(do, 0), c_dag(do, 0))

    ed.set_g2_iwn(p.G_iw[up][0, 0], c(up, 0), c_dag(up, 0))
    ed.set_g2_iwn(p.G_iw[do][0, 0], c(do, 0), c_dag(do, 0))

    p.magnetization = ed.get_expectation_value(0.5 * mA)

    p.O_tau = Gf(mesh=MeshImTime(beta, 'Fermion', 400), target_shape=[])
    ed.set_g2_tau(p.O_tau, n(up, 0), n(do, 0))
    p.O_tau.data[:] *= -1.

    p.exp_val = ed.get_expectation_value(n(up, 0) * n(do, 0))

    # ------------------------------------------------------------------
    # -- Store to hdf5

    filename = 'data_pyed_h_field_%4.4f.h5' % h_field
    with HDFArchive(filename, 'w') as res:
        res['p'] = p
Ejemplo n.º 10
0
def ctqmc_solver(h_int_, G0_iw_):

    # --------- Construct the CTHYB solver ----------
    if solver == "triqs":
        constr_params = {
            'beta': beta,
            'gf_struct': gf_struct,
            'n_iw': n_iw,
            'n_tau': 10000,  # triqs value
            'n_l': 50,
            #'complex': True   # only necessary for w2dyn
        }
    elif solver == "w2dyn":
        constr_params = {
            'beta': beta,
            'gf_struct': gf_struct,
            'n_iw': n_iw,
            'n_tau': 9999,  # w2dyn value
            'n_l': 50,
            'complex': True  # only necessary for w2dyn
        }
    S = Solver(**constr_params)

    # --------- Initialize G0_iw ----------
    S.G0_iw << G0_iw_

    # --------- Solve! ----------
    solve_params = {
        'h_int': h_int_,
        'n_warmup_cycles': n_warmup_cycles,
        #'n_cycles' : 1000000000,
        'n_cycles': n_cycles,
        'max_time': max_time,
        'length_cycle': length_cycle,
        'move_double': True,
        'measure_pert_order': True,
        'measure_G_l': True
    }

    #start = time.time()
    print 'running solver...'

    process = psutil.Process(os.getpid())
    print "memory info before: ", process.memory_info(
    ).rss / 1024 / 1024, " MB"

    S.solve(**solve_params)

    process = psutil.Process(os.getpid())
    print "memory info after: ", process.memory_info().rss / 1024 / 1024, " MB"

    print 'exited solver rank ', rank
    #end = time.time()

    G_iw_from_legendre = G0_iw_.copy()
    G_iw_from_legendre << LegendreToMatsubara(S.G_l)
    print 'G_iw_from_legendre', G_iw_from_legendre
    ##exit()

    ### giw from legendre, calculated within the interface
    #print 'S.G_iw_from_leg', S.G_iw_from_leg
    #exit()

    n_tau = 200
    tau_mesh2 = MeshImTime(beta, 'Fermion', n_tau)
    my_G_tau = BlockGf(mesh=tau_mesh2, gf_struct=gf_struct)
    print 'S.G_tau["bl"][:,:].data ', S.G_tau["bl"][:, :].data.shape

    my_G_tau["bl"][:, :].data[...] = S.G_tau["bl"][:, :].data.reshape(
        200, 50, N_bands * 2, N_bands * 2).mean(axis=1)

    #return my_G_tau, S.G_iw_from_leg
    #return my_G_tau, S.G_iw
    if solver == 'triqs':
        return my_G_tau, G_iw_from_legendre, S.average_sign
    else:
        return my_G_tau, S.G_iw_from_leg, S.average_sign