Best-approximation error for parametric quantum circuits

Understand

In Variational Quantum Simulations, the construction of a suitable parametric quantum circuit is subject to two counteracting effects.

• The number of parameters should be small for the device noise to be manageable, but also large enough for the circuit to be able to represent the solution.
• Dimensional expressivity analysis can optimize a candidate circuit considering both aspects.
• In this article, we will first discuss an inductive construction for such candidate circuits.