Questions tagged [pymatching]
The pymatching tag has no usage guidance.
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What is OBSERVABLE_INCLUDE in Stim and what is usefulness Pymatching
I have a question about the role of OBSERVABLE_INCLUDE within Stim circuits and how Pymatching uses it in order to decode syndromes. As far as I have understood from the documentation, ...
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Is it possible to adjust the weights of a pymatching graph after it is created?
I'd like to adjust the characteristics of a pymatching graph (specifically the edge weights of individual edges) to explore the effects on the decoding process.
While the ...
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Pymatching: Will starting with arbitrary weights affect the MWPM decoding process?
I am trying to examine the effect of weights on the performance of MWPM decoder on 5-repetition code as a simple example from Pymatching2. The idea is to vary the input weights by changing the error ...
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Using Pymatching to decode lattice surgery process
I want to simulate the error correction procedure for a CNOT gate on surface code and RHG cube, made by the lattice surgery process of "merge and split".
In this case, the code has an H-...
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How to compute Z logical operators of a toric code using Kunneth theorem?
I'm going through pymatching tutorial on constructing a toric code using hypergraph product of two repetition codes.
The hypergraph product code construction $H G P\left(H_1, H_2\right)$ takes as ...
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How can I decode errors in the multiple rounds of the surface code in pymatching?
The parity check matrix is 5x13. I run a distance three surface code with 3 rounds for each shot.
The syndrome measurement results are as follows for the first shot:
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Finding the number of Failure for Surface Code by using Pymatching (without STIM): ValueError: The shape of the syndrome vector z is not valid
I run the surface code for distance-3 with 3 round. I am now trying to decode and find the number of failures. My error probability of 0.08.
Here are my syndrome results:
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View/Add unconnected nodes in PyMatching
I have a repetition code like below. Since I have no SPAM error, some detectors are unconnected nodes. I cannot see the nodes from pymatching.Matching.edges(), but I can see they exist in the graph ...
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Pymatching: 'Matching' object has no attribute 'decode_batch'
I am trying to run the example from documentation: pymatching docs
Here is my code:
...
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Using Deterministic Errors in Stim Detector Circuit and decoding with Pymatching: X_ERROR(1) failing in PyMatching
the Question
Is there a standard way to use deterministic errors (so, for instance, X_ERROR(1)) in Stim with PyMatching? Currently, sometimes if I use ...
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Can Stim and PyMatching analyze logical error rate of non-deterministic observable?
In Stim, logical observable has to be deterministic. To calculate the logical error rate, we compare the actual_observables sampled with stim circuit and ...
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How is the match graph extracted from a stim.circuit.detector_error_model?
Let's say we have an error mechanism error(0.1) D7 D8 ^ D9 D10 ^ D13 D15. I understand that Stim is trying to decompose the complex errors into graphlike errors. It ...
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Pymatching, Parity Check Matrix with Syndrome Measurements and Detection Events
I am running distance 3 surface code with 3 rounds:
Here is the parity check matrix of X stabilizers for distance three surface code:
...
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Are there open source implementations of quantum error correction decoders?
To detect and correct for errors in a topological quantum memory (toric code for example) one needs a quantum error correction algorithm also known as decoder.
The minimum weight perfect matching (...
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Do detection events mean temporal and spatial coordinates?
In pymatching, the check_matrix structure is for stabilizers rather than measurement outcome of stabilizers.
I want to plot "matching" for my measurement outcomes.To do that, I need to ...
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Pymatching shows a large timing distribution to decode the same set of syndromes
I am interested in looking into histogram distributions of decoder timing for different syndrome inputs (sourced from stim) into pymatching. Unfortunately, it seems the histograms I product are more a ...
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Using PyMatching for CSS code with more than two Stabilizers per qubit
I am implementing QEC cycles for CSS codes and using PyMatching for decoding. Since I can quickly obtain the parity-check matrix, PyMatching is convenient. However, when I try to use it for CSS codes ...
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3D Toric Code using Pymatching - Logical Matrix Construction
I am trying to follow the example in the PyMatching documentation for simulating the 2D toric code with periodic BCs, and extend this to a 3D toric code with periodic BCs. I have managed to construct ...
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Check_matrix in Pymatching and Understanding the Plot
In the simplest case, let's assume we have distance 2 surface code. The X stabilizers will be: X1X2X3 and X3X4X5 which is shown by the red lines.
So the parity check matrix will be:
$$
\begin{bmatrix}...
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PyMatching.Matching.decode() returns incorrectly sized array
I have having trouble getting the decode(...) function for a pymatching.Matching object to return an array of an appropriate ...
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Pymatching Toric Code vs Surface Code
I am looking the example of toric code in Pymatching.
Here is the code:
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