8.5 QNN Embedding on NISQ QPU
Ideally, parameterised quantum circuits should be constructed in a hardware-agnostic way, only driven by the characteristics of the problem being solved. This, however, would require the existence of large and exceptionally well-connected quantum computing systems with very high qubit fidelity and coherence time. In other words, we would need QPUs with capabilities that significantly exceed those of existing NISQ devices. The time for such powerful quantum computing systems may come sooner than one may expect but we still have to find a way of running PQCs efficiently on NISQ QPUs.
8.5.1 NISQ QPU connectivity
A typical approach to designing a PQC executable on the NISQ QPU would start with observing two main characteristics of quantum computing systems: the graph (qubit connectivity) and the set of native gates. We can illustrate these points by looking at Rigetti’s Aspen system [72] in Figure 8.3.
Figure 8.3: Rigetti’...
