Beyond Quantum Computers
Giulio Chiribella, Giacomo Mauro D’Ariano, Paolo Perinotti, Benoît Valiron · arXiv (Cornell University) · 2009
The manuscript poses and addresses a new very fundamental issue in Quantum Computer Science, which is going to have a radical impact on the way we currently conceive quantum computation. We show that there exists a new kind of higher-order quantum computation, potentially much more powerful than the usual quantum processing, which is feasible, but cannot be realized by a usual quantum circuit. In order to implement this new kind of computations one needs to change the rules of quantum circuits, also considering circuits with the geometry of the connections that can be itself in a quantum superposition. The new kind of computation poses also fundamental problems for unexplored aspects of quantum mechanics in a non-fixed causal framework, which go far beyond computer-science problems, and may be of relevance in quantum gravity.