Channel matrix #4146
Channel matrix #4146
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| @pytest.mark.parametrize( | ||
| 'kraus_operators, expected_channel_matrix', | ||
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It looks like these parameterizations are reused across tests. Could you define constants for them?
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Most of the repeated constants were the Kraus operators of the completely depolarizing channel. I changed the code to use a short cirq expression to generate those instead of hardcoding. I also changed Kraus operators in another test case. The remaining constants are either different or very short (e.g. np.eye(2)). This cuts away almost all duplication (the Choi and channel matrices were of course different all along) while keeping all inputs local so the reader does not need to scroll to examine correctness.
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| def test_kraus_to_channel_matrix(kraus_operators, expected_channel_matrix): |
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To avoid confusion, expected_channel_matrix should not be reused here since it's already the name of a function in this file.
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Renamed functions to use verbs in the name.
Utility for computing perhaps the most obvious representation of quantum channels: as a matrix.
This representation allows channel application via simple matrix multiplication (where input and output density operators are vectorized) and efficient computation of entanglement fidelity (follow-up).