Matrix.Operator(M) creates an operator $O = \sum_{i,j} M[i][j] a^{\dagger}_{i-1} a_{j-1}^{\phantom{\dagger}}$ from the matrix $M$
M = {{1,2*I}, {-2*I,4}} O = Matrix.ToOperator(M) print(O)
Operator: Operator QComplex = 1 (Real==0 or Complex==1 or Mixed==2) MaxLength = 2 (largest number of product of lader operators) NFermionic modes = 2 (Number of fermionic modes (site, spin, orbital, ...) in the one particle basis) NBosonic modes = 0 (Number of bosonic modes (phonon modes, ...) in the one particle basis) Operator of Length 2 QComplex = 1 (Real==0 or Complex==1) N = 4 (number of operators of length 2) C 0 A 0 | 1.00000000000000E+00 0.00000000000000E+00 C 0 A 1 | 0.00000000000000E+00 2.00000000000000E+00 C 1 A 0 | -0.00000000000000E+00 -2.00000000000000E+00 C 1 A 1 | 4.00000000000000E+00 0.00000000000000E+00