scqubits.core.discretization.band_matrix#

scqubits.core.discretization.band_matrix(band_coeffs, band_offsets, dim, dtype=None, has_corners=False)[source]#

Returns a dim x dim sparse matrix with constant diagonals of values band_coeffs[ 0], band_coeffs[1], … along the (off-)diagonals specified by the offsets band_offsets[0], band_offsets[1], … The has_corners option allows generation of band matrices with corner elements, in which lower off-diagonals wrap into the top right corner and upper off-diagonals wrap into the bottom left corner.

Parameters:

  • band_coeffs (Union[List[float], List[complex], ndarray]) – each element of band_coeffs is a number to be assigned as a constant to the (off-)diagonals

  • band_offsets (Union[List[int], ndarray]) – offsets specifying the positions of the (off-)diagonals dim: dimension of the matrix

  • dim (int) – (linear) dimension of the matrix

  • dtype (Optional[Any]) – if not specified, dtype is inferred from the dtype of band_vecs

  • has_corners (bool) – if set to True, the off diagonals are wrapped into the opposing corners of the matrix

Return type:

csc_matrix