Teaching quantum computing using a full adder as an example

Already in 2017, the German National Academy of Sciences Leopoldina and others clearly recommended that teaching quantum phenomena must be part in basic courses of engineering education. Since optics/photonics is well known from school basic experiments on interference and wave optics are used to derive the probability interpretation of the wave function |Ψ|^2 (Born interpretation). Experiments from Grangier, Roger und Aspect (Nobel price 2022) show the particle behavior of light as well as interference and show that light propagates according to a wave equation (Schrödinger equation) and is detected as a particle. With this knowledge quantum bits (Qubits) are introduced and described in Hilbert space and by a transformation that preserves probability (length) and orthogonality: unitary matrices. We show some properties of unitary matrices and their impact on quantum gates and quantum registers. A first quantum circuit is a single- and three-coin toss simulation. We expand this knowledge to a full adder already proposed by Feynman in 1982. We simulate Feynman’s proposal and our own solution of a full adder. The proposed way is a first step to teach engineers the quantum computing basics.