Tensors and Groups in Quantum¶
A rank-k tensor \(\hat T_k^q\) is defined as
Wigner-Eckart theorem is
where \(j,j'\) are the angular momentum quantum numbers and \(n, n'\) are quantum numbers which are not related to angular momentum.
It seems that tensor \(\hat T_k^q\) is a source of angular momentum. The maximum angular momentum it can provide is \(k\).