.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/QuantumIsing_1d_quench.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_auto_examples_QuantumIsing_1d_quench.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_examples_QuantumIsing_1d_quench.py:


Quench of the quantum Ising model starting from the ground state.
=================================================================

.. GENERATED FROM PYTHON SOURCE LINES 16-130

.. code-block:: Python


    # pylint: disable=too-many-arguments
    # pylint: disable=invalid-name

    import os

    # pylint: disable-next=no-member, no-name-in-module
    import os.path

    import matplotlib.pyplot as plt
    import numpy as np

    import qtealeaves as qtl
    from qtealeaves.models import get_quantum_ising_1d

    # Keys are L, g_init, tau,  symmetry sector, value is final energy at g_final=0
    ref_osmps = {
        (8, 2.0, 10, None): -6.88725731743711,
        (8, 2.0, 10, 0): None,
        (8, 2.0, 10, 1): None,
    }


    # pylint: disable-next=too-many-locals
    def main(tn_type=5, output_folder=None, timesteps=200, plot=True):
        """
        Main method for quenching the quantum Ising model starting in a
        ground state.

        **Arguments**

        tn_type : int, optional
            Choose 5 for python-TTN, 6 for python-MPS.
            Default to 5.

        output_folder : str | None, optional
            Output folder. Default to None.

        timesteps : int, optional
            Number of timesteps. Default to 160.

        plot : bool, optional
            If True, plot the results at the end of the example. Default tot True
        """
        if output_folder is None:
            output_folder = lambda params: "QI1dDyn_L%d" % (params["L"])

        model, my_ops = get_quantum_ising_1d()

        my_conv = qtl.convergence_parameters.TNConvergenceParameters(
            max_iter=7, max_bond_dimension=20
        )
        my_obs = qtl.observables.TNObservables()

        # Dynamics
        nn_meas = 10
        quench = qtl.DynamicsQuench(
            "t_grid", measurement_period=nn_meas, time_evolution_mode=1
        )
        quench["g"] = lambda tt, params: 2.0 - 2.0 * (tt / 10.0)

        simulation = qtl.QuantumGreenTeaSimulation(
            model,
            my_ops,
            my_conv,
            my_obs,
            tn_type=tn_type,
            folder_name_output=output_folder,
            store_checkpoints=False,
        )

        params = []

        params.append(
            {
                "L": 8,
                "J": 1.0,
                "g": 2.0,
                "t_grid": [0.05] * timesteps,
                "Quenches": [quench],
                "exclude_from_hash": ["Quenches"],
            }
        )

        simulation.run(params, delete_existing_folder=True)

        for elem in params:
            obs_quench_1 = simulation.get_dynamic_obs(elem)
            energies = obs_quench_1["energy"]

            if plot:
                fig = plt.figure()
                ax1 = fig.add_subplot(111)
                ax1.plot(
                    np.cumsum(elem["Quenches"][0].get_dt_grid(elem))[::nn_meas],
                    energies,
                    "b-",
                )
                ax1.set_xlabel("Time t")
                ax1.set_ylabel("Energy E")
                # pylint: disable-next=no-member
                plt.savefig(os.path.join(output_folder(elem), "dyn_energy.pdf"))

        print(
            f"\nExample `{__file__}` ran successfully; "
            + "pdf-figures are saved to QI1dDyn; "
            + "no asserts are implemented for this example."
        )

        return


    if __name__ == "__main__":
        main()


.. _sphx_glr_download_auto_examples_QuantumIsing_1d_quench.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: QuantumIsing_1d_quench.ipynb <QuantumIsing_1d_quench.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: QuantumIsing_1d_quench.py <QuantumIsing_1d_quench.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: QuantumIsing_1d_quench.zip <QuantumIsing_1d_quench.zip>`


.. only:: html

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

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_