QUANTUM INTERFEROMETERS, EULER ANGLES, UNITARY REPRESENTATIONS OF SU(2)

The “one particle” and the “two particles” interferometers can be (quantum mechanically) described in terms of Hilbert spaces of states and scattering operators. In this case the scattering operators realize a unitary representation of SU(2) and the Euler angles of the SU(2) group are related to the interferometers parameters (transmission coefficients, phase shifts).