feat: Crosstalk Payload #191
Conversation
… noise channel for the it
…omes so that we can apply the transitiosn
…ys from the model
…that accumulates the outcomes of user-issued measurements and returns that only at Complete stage. This allows us to do multiple rounds of communication between the simulator and the noise model via NeedsProcessing.
… and 1->1 so that it matches the behaviour of previous simple crosstalk channel
PabloAndresCQ
left a comment
PabloAndresCQ
left a comment
There was a problem hiding this comment.
Ready for review. Some comments below to give context to the changes
| measured_qubits: Vec<(usize, GateType)>, | ||
|
|
||
| /// Stored outcome builder | ||
| results_builder: ByteMessageBuilder, |
There was a problem hiding this comment.
Keeps track of the outcomes that need to be sent back once continue_processing returns Complete(O). This is so that we can have multiple rounds of NeedsProcessing(I) and accummulate the outcomes until we are ready to return them.
| .iter() | ||
| .map(|q| (usize::from(*q), gate.gate_type)), | ||
| ); | ||
| } |
There was a problem hiding this comment.
Moved this out because it's necessary to keep track of measured_qubits even if Measure and/or MeasureLeaked are contained in noiseless_gates.
| } | ||
| self.apply_prep_faults(&gate, &mut builder); | ||
| self.apply_crosstalk_faults(&gate, self.p_prep_crosstalk, &mut builder); | ||
| self.apply_simple_crosstalk_faults(&gate, self.p_prep_crosstalk, &mut builder); |
There was a problem hiding this comment.
Prep still uses the old crosstalk channel. In Selene we currently set p_prep_crosstalk = 0.0.
| // Build and return the biased measurement results | ||
| Ok(results_builder.build()) | ||
| self.results_builder.add_outcomes(&outcomes); | ||
| Ok(ops_builder.build()) |
There was a problem hiding this comment.
apply_noise_on_continue_processing now always returns a ByteMessage of quantum_ops and appends the outcomes to the new field self.results_builder. It's continue_processing the one that, if this ByteMessage is empty, flushes the results_builder and sends it via Complete(O).
Description
MeasCrosstalkLocalPayloadandMeasCrosstalkGlobalPayloadto communicate details from runtime necessary to model crosstalk more realistically.p_meas_crosstalkhas been replaced byp_meas_crosstalk_globalandp_meas_crosstalk_local. The methodwith_p_meas_crosstalkfrom the builder now sets both of these parameters to the given value. There are also individualwith_*methods for global and local.p_meas_crosstalk_modelfor the transition probabilities after crosstalk-induced Z projection on the victim qubits.Discussion
p_meas_crosstalk_model = {"0->0": 1.0, "1->1: 0.0"}and usingwith_p_meas_crosstalk, the model reproduces the previous implementation of the channel... with one important caveat: PECOS does not itself introduceMeasCrosstalk*Payloadinstructions which are the ones that trigger the crosstalk channels.explicit_meas_crosstalk(that Selene always sets to True) where, if False, causes PECOS to assume it won't receiveMeasCrosstalk*Payloadoperations and instead needs to callapply_crosstalk_faults_from_payload()when encounteringMeasureorMeasureLeaked.