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1 vote
Accepted

Obtaining and Applying XX and ZZ Parity in Stim for Controlled Paulis

Stim's supported gates documentation includes the gate MXX and the gate MZZ which are exactly the two-qubit parity measurement ...
Craig Gidney's user avatar
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1 vote
Accepted

Does the threshold estimation of the surface code not need a fault-tolerant setup?

I think technically, if you want to ensure Fault-Tolerance, indeed you need Shor/Steane/Knill error correction. e.g. in the surface code case, you need weight-4 cat state to do syndrome measurement ...
AndyLiuin's user avatar
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1 vote

Does the threshold estimation of the surface code not need a fault-tolerant setup?

Is this still a fault-tolerant scheme? Can't an error in an ancilla spread to multiple data qubits and cause a logical error? Why would "fault tolerance" hinge on whether or not an error in ...
Craig Gidney's user avatar
  • 38.6k
1 vote

Does the threshold estimation of the surface code not need a fault-tolerant setup?

What does it mean to have a fault-tolerant setup? This has been done most rigorously for distance 3 codes, in which case a sufficient condition for a gate to be fault tolerant is that it should ...
DaftWullie's user avatar
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1 vote

explain_detector_error_model_errors complains "no single circuit error had these exact symptoms"

That method is for turning the detection events of a single dem error into possible circuit errors causing that dem error. It doesn't do general decoding, as that is way way harder. So it doesn't work ...
Craig Gidney's user avatar
  • 38.6k
1 vote
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What is TICK layer in stim

In Stim, TICK is an instruction that does nothing except indicate the passage of time. Conceptually, ticks split the circuit up into steps. Ticks have no effect on ...
Craig Gidney's user avatar
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