qiskit_addon_sqd.fermion.bitstring_matrix_to_sorted_addresses

bitstring_matrix_to_sorted_addresses(bitstring_matrix, open_shell=False)

Convert a bitstring matrix into a sorted array of unique, unsigned integers.

This function separates each bitstring in bitstring_matrix in half, flips the bits and translates them into integer representations, and finally appends them to their respective (spin-up or spin-down) lists. Those lists are sorted and output from this function.

Deprecated since version 0.6.0: The function qiskit_addon_sqd.fermion.bitstring_matrix_to_sorted_addresses() is deprecated as of qiskit-addon-sqd 0.6.0. It will be removed no sooner than qiskit-addon-sqd 0.8.0. Use the bitstring_matrix_to_ci_strs function.

Parameters:

  • bitstring_matrix (ndarray) – A 2D array of bool representations of bit values such that each row represents a single bitstring

  • open_shell (bool) – A flag specifying whether unique addresses from the left and right halves of the bitstrings should be kept separate. If False, addresses from the left and right halves of the bitstrings are combined into a single set of unique addresses. That combined set will be returned for both the left and right bitstrings.

Returns:

A length-2 tuple of sorted, unique determinants representing the left (spin-down) and right (spin-up) halves of the bitstrings, respectively.

Return type:

tuple[ndarray, ndarray]