Hello!
I'm trying to enhance the calculation time for exponential operator,and
the form is exp(1j*(a*Jx+Jy*b)) .
Jx and Jy are angular momentum operators ,and when angular momentum quantum number is very large,it takes
very long time to get the exponential operator.
For that reason, I'm trying to use diagonalized form of the exponent.
The problem is that I don't know how to construct diagonalization block matrix from eigenvectors in qutip.
I tried to make a matrix from qutip eigenvectors, but I can't make numpy matrix from qutip objects.
I can't use vector data only from qutip object ,and it is hard to make matrix from the vectors.
How can I make an operator from qutip vectors?
I also wonder if there is a simple method to convert qutip ket vector array to bra vector array
dag() convert only one vector at once.
Thanks in advance()
