Exemple #1
0
def make_calc():

    # ------------------------------------------------------------------
    # -- Hamiltonian

    p = ParameterCollection(
        beta = 0.5,
        U = 0.5,
        nw = 1,
        nwf = 15,
        V = 1.0,
        eps = 0.2,
        )

    p.nwf_gf = 4 * p.nwf
    p.mu = 0.5*p.U

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

    ca_up, cc_up = c('0', 0), c_dag('0', 0)
    ca_do, cc_do = c('0', 1), c_dag('0', 1)

    ca0_up, cc0_up = c('1', 0), c_dag('1', 0)
    ca0_do, cc0_do = c('1', 1), c_dag('1', 1)

    docc = cc_up * ca_up * cc_do * ca_do
    nA = cc_up * ca_up + cc_do * ca_do
    hybridiz = p.V * (cc0_up * ca_up + cc_up * ca0_up + cc0_do * ca_do + cc_do * ca0_do)
    bath_lvl = p.eps * (cc0_up * ca0_up + cc0_do * ca0_do)

    p.H_int = p.U * docc
    p.H = -p.mu * nA + p.H_int + hybridiz + bath_lvl

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

    # Conversion from TRIQS to Pomerol notation for operator indices
    # TRIQS:   block_name, inner_index
    # Pomerol: site_label, orbital_index, spin_name
    index_converter = {
        ('0', 0) : ('loc', 0, 'up'),
        ('0', 1) : ('loc', 0, 'down'),
        ('1', 0) : ('loc', 1, 'up'),
        ('1', 1) : ('loc', 1, 'down'),
        }

    # -- Create Exact Diagonalization instance
    ed = PomerolED(index_converter, verbose=True)
    ed.diagonalize(p.H) # -- Diagonalize H

    p.gf_struct = [['0', [0, 1]]]

    # -- Single-particle Green's functions
    p.G_iw = ed.G_iw(p.gf_struct, p.beta, n_iw=p.nwf_gf)['0']

    # -- Particle-particle two-particle Matsubara frequency Green's function
    opt = dict(
        beta=p.beta, gf_struct=p.gf_struct,
        blocks=set([("0", "0")]),
        n_iw=p.nw, n_inu=p.nwf)

    p.G2_iw_ph = ed.G2_iw_inu_inup(channel='PH', **opt)[('0', '0')]

    filename = 'data_pomerol.h5'
    with HDFArchive(filename,'w') as res:
        res['p'] = p

    import os
    os.system('tar czvf data_pomerol.tar.gz data_pomerol.h5')
    os.remove('data_pomerol.h5')
Exemple #2
0
def make_calc():

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

    p = ParameterCollection(
        beta=1.0,
        U=5.0,
        nw=1,
        nwf=20,
    )

    p.nwf_gf = 4 * p.nwf
    p.mu = 0.5 * p.U

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

    ca_up, cc_up = c('0', 0), c_dag('0', 0)
    ca_do, cc_do = c('0', 1), c_dag('0', 1)

    docc = cc_up * ca_up * cc_do * ca_do
    nA = cc_up * ca_up + cc_do * ca_do
    p.H = -p.mu * nA + p.U * docc

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

    # Conversion from TRIQS to Pomerol notation for operator indices
    # TRIQS:   block_name, inner_index
    # Pomerol: site_label, orbital_index, spin_name
    index_converter = {
        ('0', 0): ('loc', 0, 'up'),
        ('0', 1): ('loc', 0, 'down'),
    }

    # -- Create Exact Diagonalization instance
    ed = PomerolED(index_converter, verbose=True)
    ed.diagonalize(p.H)  # -- Diagonalize H

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

    # -- Single-particle Green's functions
    p.G_iw = ed.G_iw(gf_struct, p.beta, n_iw=p.nwf_gf)['0']

    # -- Particle-particle two-particle Matsubara frequency Green's function
    opt = dict(beta=p.beta,
               gf_struct=gf_struct,
               blocks=set([("0", "0")]),
               n_iw=p.nw,
               n_inu=p.nwf)

    p.G2_iw_ph = ed.G2_iw_inu_inup(channel='PH', **opt)[('0', '0')]

    # ------------------------------------------------------------------
    # -- Generalized susceptibility in magnetic PH channel

    p.chi_m = Gf(mesh=p.G2_iw_ph.mesh, target_shape=[1, 1, 1, 1])
    p.chi_m[0, 0, 0, 0] = p.G2_iw_ph[0, 0, 0, 0] - p.G2_iw_ph[0, 0, 1, 1]

    p.chi0_m = chi0_from_gg2_PH(p.G_iw, p.chi_m)
    p.label = r'Pomerol'

    # ------------------------------------------------------------------
    # -- Generalized susceptibility in PH channel

    p.chi = chi_from_gg2_PH(p.G_iw, p.G2_iw_ph)
    p.chi0 = chi0_from_gg2_PH(p.G_iw, p.G2_iw_ph)
    p.gamma = inverse_PH(p.chi0) - inverse_PH(p.chi)

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

    filename = 'data_pomerol.h5'
    with HDFArchive(filename, 'w') as res:
        res['p'] = p