---
features:
  - |
    Add approximation to the `"matrix_product_state"` simulation method of the
    :class:`~qiskit.providers.aer.QasmSimulator` to limit the bond-dimension of
    the MPS.

    There are two modes of approximation. Both discard the smallest 
    Schmidt coefficients following the SVD algorithm.
    There are two parameters that control the degree of approximation:
    ``"matrix_product_state_max_bond_dimension"`` (int): Sets a limit
    on the number of Schmidt coefficients retained at the end of
    the svd algorithm. Coefficients beyond this limit will be discarded.
    (Default: None, i.e., no limit on the bond dimension).
    ``"matrix_product_state_truncation_threshold"`` (double):
    Discard the smallest coefficients for which the sum of
    their squares is smaller than this threshold.
    (Default: 1e-16).
  - |
    Improve the performance of measure sampling when using the
    `"matrix_product_state"` :class:`~qiskit.providers.aer.QasmSimulator`
    simulation method.
