Implement PhasedXZGate._unitary_ #4617
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| gate = cirq.PhasedXZGate.from_matrix(unitary) | ||
| kraus = cirq.kraus(gate) | ||
| assert len(kraus) == 1 | ||
| cirq.testing.assert_allclose_up_to_global_phase(kraus[0], unitary, atol=1e-8) |
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Question: is this tol too high for complex64. I would've expected only around 6-7 decimal digits of reliability.
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This was copy-pasted from other allclose checks in the same module. I'm inclined to keep it for consistency, but we could certainly relax it throughout the module if desired.
| np.array([[0, 1], [1j, 0]]), | ||
| ], | ||
| ) | ||
| def test_from_matrix_close_kraus(unitary: np.ndarray): |
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Can we add another test that hits cirq.unitary as well ?
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There is already a test of cirq.unitary: https://github.com/quantumlib/Cirq/blob/master/cirq-core/cirq/ops/phased_x_z_gate_test.py#L196. This worked by decomposition even without a _unitary_ implementation, but other protocols like cirq.kraus didn't.
Fixes #3965. Fixes #4434.