The unitary property of S-matrix is directly related to the conservation of the probability current in quantum mechanics. ... This implies the S-matrix is a unitary matrix.

Is scattering matrix Hermitian?

, the scattering matrix operator, S , is a real, symmetric and hermitian operator and it is. A three-dimensional transmission-line matrix (TLM) model was developed to simulate microwave-scanning microscopy.

Is time evolution unitary?

The evolution in time of a quantum system is represented by unitary operators which preserve distinctions and overlap.