Ansatz library brainstorming

[gatorwatt]

The impression I got from tutorials was that in general, other than for random gates, the convention is that quantum circuit ansatz are constructed manually. (If I am mistaken about this point then please feel free to disregard.) Would it be possible to assemble a library of common ansatz architecture initialization functions that can be initialized in simpler fashion by just designating a few points like qubit count and etc? Please consider this brainstorming.

[lockwo]

This is similar to something I previously discusses, with relation to input embeddings (see #391). Maybe having something like a template class (similar to pennylane https://pennylane.readthedocs.io/en/stable/introduction/templates.html) which has common data encoders and circuit structures is an idea. Not sure how much work that would require, so it may or may not be worthwhile.

[gatorwatt]

Yeah is not clear to me how varied are types of common ansatz. The tensorflow quantum paper demonstrates a few, wasn’t sure if these forms are like authoritative accepted mainstream architectures or just starting points.