Adds bit and phase flip channels #954
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## master #954 +/- ##
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Coverage 97.82% 97.82%
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Files 149 149
Lines 10237 10259 +22
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+ Hits 10014 10036 +22
Misses 223 223
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glassnotes
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core 
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Since these are so urprised these weren't in the previous PR that added channels 🤔 |
pennylane/ops/channel.py
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| @@ -223,6 +223,90 @@ def _kraus_matrices(cls, *params): | |||
| return [K0, K1, K2, K3] | |||
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| class BitFlipChannel(Channel): | |||
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I actually like dropping the "Channel" and naming these BitFlip and PhaseFlip. The only case we had "Channel" in the name I believe was for DepolarizingChannel, which makes sense since just Depolarizing is a bit akward
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Fair enough! How do you feel about BitFlipError and PhaseFlipError? I'd like to have something to denote that they are error channels and not just regular operations (also I just noticed I that this is what I called them in the changelog... 🤦)
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I have this discussion with Alain all the time...
I personally prefer names to be implicit and short, rather than explicit and long. So while you're right that a "BitFlip" could potentially be interpreted as a regular operation (apply PauliX), it will likely be clear from context and from a good docstring that this is not the case. The more compact name then leads to cleaner and shorter code.
tests/ops/test_channel_ops.py
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| assert np.allclose(op(0, wires=0).kraus_matrices[0], np.eye(2), atol=tol, rtol=0) | ||
| assert np.allclose(op(0, wires=0).kraus_matrices[1], np.zeros((2, 2)), atol=tol, rtol=0) | ||
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| def test_p_arbitrary(self, tol): |
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This is fine, but it's good practice to run tests for several parameter values. This is usually done using the parametrize decorator
@pytest.mark.parametrize("p", [0.1, 0.4, 0.7])
def test_p_arbitrary(self, p, tol)There was a problem hiding this comment.
Good call, this allows for merging the two separate tests into a single parameterized test.
Co-authored-by: ixfoduap <40441298+ixfoduap@users.noreply.github.com>
Co-authored-by: ixfoduap <40441298+ixfoduap@users.noreply.github.com>
Context: Bit flips and phase flips are commonly occurring errors. As we begin doing more noisy simulations with the
default.mixeddevice, it will be convenient to have these error channels available.Description of the Change: Adds two new error channels,
BitFlipChannelandPhaseFlipChannel(and associated documentation and tests).Benefits: Adds to a growing library of errors to make noisy simulations more flexible.
Possible Drawbacks: None
Related GitHub Issues: None