.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/RydbergRb87_3d_groundstate.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_RydbergRb87_3d_groundstate.py>`
        to download the full example code.

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

.. _sphx_glr_auto_examples_RydbergRb87_3d_groundstate.py:


Ground state search for a Rydberg system (Rb87)
===============================================

Rb87 with Rydberg state 70s1/2) in a 3d setup.

.. GENERATED FROM PYTHON SOURCE LINES 17-98

.. code-block:: Python


    # pylint: disable=invalid-name

    import numpy as np
    import numpy.linalg as nla

    import qtealeaves as qtl
    from qtealeaves import modeling


    def main(tn_type=5, output_folder=None):
        """
        Main method for the ground state search of the 3d Rydberg model.

        **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.
        """
        model_name = lambda params: "Rydberg_L%d" % (params["L"])
        if output_folder is None:
            output_folder = lambda params: "Rb87_L%d" % (params["L"])

        model = modeling.QuantumModel(3, "L", name=model_name)

        model += modeling.LocalTerm("sx", strength="Jx")
        model += modeling.LocalTerm("n", strength="U")

        model += modeling.TwoBodyTerm3D(["n", "n"], [1, 0, 0], strength="V1")
        model += modeling.TwoBodyTerm3D(["n", "n"], [1, 1, 0], strength="V2")
        model += modeling.TwoBodyTerm3D(["n", "n"], [1, 1, 1], strength="V3")
        model += modeling.TwoBodyTerm3D(["n", "n"], [2, 0, 0], strength="V4")

        my_conv = qtl.convergence_parameters.TNConvergenceParameters(
            max_iter=3, max_bond_dimension=2
        )
        my_ops = qtl.operators.TNSpin12Operators()
        my_obs = qtl.observables.TNObservables()
        my_obs += qtl.observables.Local("<sx>", "sx")

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

        params = [
            {"L": 4, "Jx": 2.0, "U": -15.0, "V1": 25.0, "V2": 3.12, "V3": 0.92, "V4": 0.39}
        ]

        simulation.run(params, delete_existing_folder=True)

        for elem in params:
            tn_energy_0 = simulation.get_static_obs(elem)["energy"]

            if elem["L"] == 2:
                ed_energy_0 = nla.eigh(model.build_ham(my_ops, elem))[0][0]
                print("TN vs ED ground state energy", tn_energy_0, ed_energy_0)

                assert np.abs(tn_energy_0 - ed_energy_0) < 1e-4
                msg_check = "ground state energy at least correct up to 1e-4."

            else:
                print("TN ground state energy", tn_energy_0)
                msg_check = "no asserts implemented for this system size."

        print(f"\nExample `{__file__}` ran successfully; {msg_check}")

        return


    if __name__ == "__main__":
        main()


.. _sphx_glr_download_auto_examples_RydbergRb87_3d_groundstate.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: RydbergRb87_3d_groundstate.ipynb <RydbergRb87_3d_groundstate.ipynb>`

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

      :download:`Download Python source code: RydbergRb87_3d_groundstate.py <RydbergRb87_3d_groundstate.py>`

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

      :download:`Download zipped: RydbergRb87_3d_groundstate.zip <RydbergRb87_3d_groundstate.zip>`


.. only:: html

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

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