pygsti.std_matrices¶
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pygsti.
std_matrices
(dimOrBlockDims)¶ Get the elements of the matrix unit, or “standard”, basis spanning the density-matrix space given by dimOrBlockDims.
The returned matrices are given in the standard basis of the “embedding” density matrix space, that is, the space which embeds the block-diagonal matrix structure stipulated in dimOrBlockDims. These matrices form an orthonormal basis under the trace inner product, i.e. Tr( dot(Mi,Mj) ) == delta_ij.
Parameters: dimOrBlockDims (int or list of ints) – Structure of the density-matrix space. Returns: A list of N numpy arrays each of shape (dmDim, dmDim), where dmDim is the matrix-dimension of the overall “embedding” density matrix (the sum of dimOrBlockDims) and N is the dimension of the density-matrix space, equal to sum( block_dim_i^2 ). Return type: list Notes
Each element is a matrix containing a single “1” entry amidst a background of zeros, and there are never “1”s in positions outside the block-diagonal structure.