Add loss policies to NoiseConfig to express different kinds of behavior on lost qubits#3302
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orpuente-MS wants to merge 8 commits into
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Add loss policies to NoiseConfig to express different kinds of behavior on lost qubits#3302orpuente-MS wants to merge 8 commits into
NoiseConfig to express different kinds of behavior on lost qubits#3302orpuente-MS wants to merge 8 commits into
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orpuente-MS
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billti
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| @pytest.mark.parametrize("sim_type", LOSS_POLICY_SIM_TYPES) | ||
| def test_on_loss_swap_skip_keeps_state_but_swaps_loss_flag(sim_type): | ||
| # Overriding `swap.on_loss` to SKIP skips the SWAP unitary, but the loss | ||
| # flag is still exchanged. qs[0] keeps its reset |0> and qs[1] becomes lost. |
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This one is interesting. Worth discussing more. Seems odd you would skip the unitary (which swaps the state) but still swap which is lost. Not sure if that would be physically possible.
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Mmh, maybe the behavior here should be:
SKIPdoesn't apply the unitary nor exchanges loss flags.APPLY_ANYWAYapplies the unitary and exchanges the loss flags.
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billti
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| self.state.apply_unitary(UnitaryOp::ControlledX, &[q2, q1]); | ||
| } | ||
| } | ||
| } else { |
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In a number of these, you're not applying idle noise on the other qubit.
Also, for ApplyAnyway (which we should discuss further as it doesn't make much sense to me), should you also be applying idle noise anyway to the lost qubits?
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Added the missing idle noise applications.
We can discuss removing the ApplyAnyway policy.
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With this change, users are able to specify how gates should behave if at least one of their qubit operands is lost. Below is a comprehensive example, showing all 5 loss policies.