def set_tensor_linop_backend(backend):
    """Set the default backend used for tensor network linear operators, via
    'opt_einsum'. This is different from the default contraction backend as
    the contractions are likely repeatedly called many times.

    See Also
    --------
    get_tensor_linop_backend, set_contract_backend, get_contract_backend,
    TNLinearOperator
    """
    global _TENSOR_LINOP_BACKEND
    _TENSOR_LINOP_BACKEND = backend
