quil-lang / quilc

The optimizing Quil compiler.
Apache License 2.0
454 stars 73 forks source link

Fidelity calculations can be numerically unstable #803

Open stylewarning opened 2 years ago

stylewarning commented 2 years ago

In PR #802 we recognized that RZ is such a small number that in larger calculations of gate sequence fidelities, it gets completely lost, leading to imprecise compilation. In that same PR, there was a lot of discussion on how one might remediate it, including assigning a slightly different notion of fidelity.

Investigate that thread and revamp how we express fidelities.

Labeling as "bug" even though it's quite a soft bug.