TensorProduct[PauliMatrix[1], DiagonalMatrix[{1, 1}]] // TableForm
created a tensor, which could be flatten to table form. However, how to make the tensor into a matrix?
KroneckerProduct[PauliMatrix[1], IdentityMatrix[2]]
MatrixForm@%
{{0, 0, 1, 0}, {0, 0, 0, 1}, {1, 0, 0, 0}, {0, 1, 0, 0}}
$\left( \begin{array}{cccc} 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ \end{array} \right)$
ArrayFlatten[TensorProduct[PauliMatrix[1], DiagonalMatrix[{1, 1}]]]
. $\endgroup$TableForm
like all other commands ending onForm
suchMatrixForm
are just for displaying purposes. Do not use them in computations. $\endgroup$