.. _sphx_glr_dimer_lattice_plot_sigma_12.py:


======================================
The change of Sigma_12
======================================





.. image:: /dimer_lattice/images/sphx_glr_plot_sigma_12_001.png
    :align: center





.. code-block:: python


    # Created Mon Mar  7 01:14:02 2016
    # Author: Óscar Nájera

    from __future__ import division, absolute_import, print_function

    from math import log, ceil
    import numpy as np
    import matplotlib.pyplot as plt
    import dmft.dimer as dimer
    from dmft import ipt_imag
    import dmft.common as gf


    def ipt_u_tp(tprange, u_int, beta):

        tau, w_n = gf.tau_wn_setup(dict(BETA=beta, N_MATSUBARA=2**11))
        giw_d, giw_o = dimer.gf_met(w_n, 0., tprange[0], 0.5, 0.)

        giw_d, giw_o, loops = dimer.ipt_dmft_loop(
            beta, u_int + 3, tprange[0], giw_d, giw_o, tau, w_n, 1e-10)
        sigma = []

        for tp in tprange:
            giw_d, giw_o, loops = dimer.ipt_dmft_loop(
                beta, u_int, tp, giw_d, giw_o, tau, w_n, 1e-10)
            g0iw_d, g0iw_o = dimer.self_consistency(
                1j * w_n, 1j * giw_d.imag, giw_o.real, 0., tp, 0.25)
            siw_d, siw_o = ipt_imag.dimer_sigma(
                u_int, tp, g0iw_d, g0iw_o, tau, w_n)
            sigma.append(siw_o.real)

        return np.array(sigma)


    tprange = np.arange(0.1, 1, 0.1)
    BETA = 512.
    tau, w_n = gf.tau_wn_setup(dict(BETA=BETA, N_MATSUBARA=2**11))
    sigma = ipt_u_tp(tprange, 3, BETA)
    plt.plot(w_n, sigma.T)
    plt.show()
    le = [np.polyfit(w_n[:2], s[:2], 1)[1] for s in sigma]
    plt.plot(tprange, sigma[:, 0])
    plt.plot(tprange, le + tprange)
    plt.show()

**Total running time of the script:** ( 0 minutes  0.709 seconds)



.. container:: sphx-glr-footer


  .. container:: sphx-glr-download

     :download:`Download Python source code: plot_sigma_12.py <plot_sigma_12.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: plot_sigma_12.ipynb <plot_sigma_12.ipynb>`

.. rst-class:: sphx-glr-signature

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