PennyLaneAI / PennyLaneAI/catalyst

Contextual decomposition strategy to improve differentiability

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enhancement
Dominant language
Python
Stars
234
Forks
84
Avg merge
2d 15h
Merged PRs (30d)
66

Description

Issue description
  • Expected behavior: QubitUnitary for gates with more than 2 qubits is not differentiable using Enzyme. This means that programs that transform gates to QubitUnitary cannot be differentiated. However, it is possible to differentiate these programs if instead of transforming gates to QubitUnitary they are decomposed to other gates.

  • Actual behavior: The decomposition strategy right now is indeed to decompose as much as possible without changing them to QubitUnitary, but once matrix gates are used, some gates will be changed to QubitUnitary.

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Research direction

No files or tests are named. Start by locating the decomposition strategy and the handling of QubitUnitary for matrix gates, then determine how contextual decomposition should preserve differentiability with Enzyme. Done means programs that would otherwise become multi-qubit QubitUnitary operations can be differentiated after decomposition.

Written by the indexing model from the issue text.

Assessment

Domain
compilers
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
20/100

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