peropq.exact_diagonalization
============================

.. py:module:: peropq.exact_diagonalization


Classes
-------

.. autoapisummary::

   peropq.exact_diagonalization.ExactDiagonalization


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

.. py:class:: ExactDiagonalization(number_of_qubits)

   Class implementing exact diagonalization for benchmarks on small system sizes.


   .. py:attribute:: number_of_qubits


   .. py:method:: pauli_to_sparse(pauli)

      Converts a Pauli to a 2x2 sparse matrix.

      param: pauli to be converted.



   .. py:method:: get_sparse(pauli_string)

      Transforms PauliString into sparse matrix.

      param: pauli_string to be transformed into a sparse matrix.



   .. py:method:: get_hamiltonian_matrix(hamiltonian)

      param: hamiltonian to be converted to sparse.



   .. py:method:: get_continuous_time_evolution(hamiltonian, time)

      Get the continuous time evolution of an Hamiltonian.

      param: hamiltonian governing the dynamics
      param: time at which we want to time evolve.



   .. py:method:: get_variational_evolution(variational_unitary)

      Get the time evolution unitary from a variational unitary.

      param: variational_unitary to be evolved.



   .. py:method:: apply_continuous_to_state(hamiltonian, time, state)

      Apply the continuous time evolution.

      param: hamiltonian governing the dynamics
      param: time at which we want to time evolve.
      param: state to be evolved.



   .. py:method:: apply_variational_to_state(variational_unitary, state)

      Apply the variational unitary to a state.

      param: variational_unitary to be applied
      param: state on which the unitary is applied



   .. py:method:: get_error(variational_unitary, hamiltonian)

      Returns the error made for by the variational unitary (compared to the continuous time evolution).

      param: variational_unitary to be compared with the continuous time evolution.
      param: hamiltonian used to caclulated the continuous time evolution.