states.chessboard
=================

.. py:module:: states.chessboard

.. autoapi-nested-parse::

   Chessboard state represent the state of a chessboard used in quantum chess.

   In a quantum chessboard, each chess piece is quantum having a superposition of channel states, giving rise to a unique
   chess piece.



Functions
---------

.. autoapisummary::

   states.chessboard.chessboard


Module Contents
---------------

.. py:function:: chessboard(mat_params, s_param = None, t_param = None)

   Produce a chessboard state :footcite:`Bruß_2000_Construction`.

   Generates the chessboard state defined in :footcite:`Bruß_2000_Construction`. Note that, for certain choices of
   :code:`s_param` and :code:`t_param`, this state will not have positive partial transpose, and
   thus may not be bound entangled.

   .. rubric:: Examples

   The standard chessboard state can be invoked using :code:`|toqito⟩` as

   .. jupyter-execute::

     from toqito.states import chessboard
     chessboard([1, 2, 3, 4, 5, 6], 7, 8)

   .. rubric:: References

   .. footbibliography::

   :param mat_params: Parameters of the chessboard state as defined in :footcite:`Bruß_2000_Construction`.
   :param s_param: Default is :code:`np.conj(mat_params[2]) / np.conj(mat_params[5])`.
   :param t_param: Default is :code:`t_param = mat_params[0] * mat_params[3] / mat_params[4]`.
   :return: A chessboard state.