dUCC in Hilbert Space

[JonathonMisiewicz]

Some quantum computing ansatze are rigorously particle-conserving. This includes the dUCC with fermionic particle-conserving operators. Can we cast these as operations in a single Hilbert space? Using the full Fock space apparatus seems unnecessarily expensive.

At present, this is a "big picture idea" and not implementable code. The next step would be to figure out where the current code uses the fact that we have all Fock space.