Quantum chaos in small quantum networks

We study a 2-spin quantum Turing architecture, in which discrete local rota tions {alpha(m)} of the Turing-head spin alternate with quantum controlled NOT operations. We show that a single chaotic parameter input {alpha(m)} le ads to a chaotic dynamics in the entire Hilbert space. The instability of p eriodic orbits on the Turing head and 'chaos swapping' onto the Turing tape are demonstrated explicitly as well as exponential parameter sensitivity o f the Bures metric.