Update docs once migration of all cirq/optimizers to cirq/transformers is completed.

[tanujkhattar]

Summarize the task
All existing optimizers in cirq-core/optimizers are being rewritten to follow the new transformer API (#4483), use new moment-preserving transformer primitives, and support no-compile tags (#4253) as part of #4722

Existing cirq docs should be updated to correctly reflect usages of new transformer primitives and new docs should be added for new features like support for no-compile tags, moment preserving nature of new transformers etc.

Acceptance criteria - when is the task considered done?

• Update existing docs
• Write new docs covering newly added features

[anonymousr007]

Hi, @tanujkhattar, this issue is still open? If, yes, I want to make a PR for this issue.

[vtomole]

Hey @anonymousr007, thanks for your inquiry. This task shouldn't be started until #4722 is closed.

[anonymousr007]

Thanks, @vtomole for the information. I want to work on #4722.

[tanujkhattar]

@anonymousr007 #4722 is already completed (I'll add a comment and close the issue soon).

This issue is indeed still open and needs to be done. A good document to update will be

https://github.com/quantumlib/Cirq/blob/master/docs/transform.ipynb

The cirq.optimizers sub-package has been deprecated completely and the new transformers are present in cirq.transformers sub-package. The above tutorial needs to be updated to reflect how to use the newly added transformers in cirq.transformers.

Each deprecated optimizer in cirq.optimizers has a deprecation msg which highlights the new transformer that should be used to replace it. You can look at tests of newly added transformers for more context on how they work. I'll be happy to provide more details and links to design docs etc. if you have specific questions.

[anonymousr007]

@tanujkhattar, Thanks for the information. I understand about deprecated of cirq.optimizers sub-package. How can we use transformers in quantum? Can you please share some good papers on it?

Some important points,

• Actually, I want to work in cirq for the next 6 months+.
• I want to understand cirq structure from basics.
• I am well experienced in Quantum Information Science (QIS) and Quantum Error Correction (QEC).

Please tell me some major issues related to qis and qec.