Parameterized quantum circuits or also known as variational circuits are quantum algorithms (from non-electronic design code) that depend on control parameters. Like standard quantum circuits, they consist of three necessary elements. The preparation of a known fixed initial state of a quantum circuit U(θ); the parametrization by a set of controllable parameters θ (usually they are angles); and, the measurement of the observable H ̂. Then, once the expected value has been calculated, it is iterated with the optimization subroutine. The last two steps are repeated until the optimal θ parameter (θ ̂) is found. In other cases, it may be multiple parameters to minimize. For example, in case of a quantum classifier, it is minimized, both θ and x.
Here I will collect all the PQC/Ansatzes that I'm experimenting