Fault tolerant preparation of Quantum Reed Muller codes of blocklength 127

This repo contains the source code of the paper "Computation with Quantum Reed-Muller codes and their mapping to 2D atom array".

Installation

Please use Python $\geq$ 3.12 and install Cython.

make
python setup.py build_ext --inplace

Building C++ program via make also works on MAC M2 chip, but I only got Cython binding working on Linux machines.

Data and log availability

The gathered ancilla and exRec simulation logs are available on Zenodo, you can download them as follows.

wget https://zenodo.org/records/14003891/files/logs_exRec.zip && unzip logs_exRec.zip && rm -rf __MACOSX
wget https://zenodo.org/records/14003891/files/logs_prep_SPAM_half_CNOT.zip && unzip logs_prep_SPAM_half_CNOT.zip
wget https://zenodo.org/records/14003891/files/logs_prep_SPAM_equal_CNOT.zip && unzip logs_prep_SPAM_equal_CNOT.zip
rm *.zip

These ancilla took supercomputer Euler twenty days to simulate, might be useful if one wants to run magic state distillation in the future. Please refer to utils.py and full_Steane.py for loading these ancilla. The propagation dictionaries are already contained there, but you can generate new ones following the comments in full_prep_sim_*.py.

logs_exRec/ contains the exRec simulation results, it also contains some useful data gathering scripts.

Run scripts

Please do mv run_scipts/* . before using the scripts to submit jobs to Slurm servers.

• run_prep.py - for full_prep_sim_*.py to simulate ancilla preparation and store residual errors
• run_exRec.py - for full_Steane.py to simulate exRec
• run_SCL.py - for simulating data qubit noise decoding
• run_test_pairs.py - for doing heuristic search of permutations

Meet-in-the-middle FT testing and malignant set counting

structured_test.py contains global MITM testing/counting across four patches up to order six. strict_FT/ stores all the logs. The following runtime estimate are based on my Linux workstation (Intel i9-13900K, 64GB memory). Order up to four takes less than half a minute.

Order five and six faults will store many order-three fault dictionaries on disk. When loading them back to do MITM, peak memory usage exceeds 50GB.

• state0_Z and state+_X store 68G on disk, runtime ~6h
• state0_X and state+_Z store 29G on disk, runtime ~1.5h

Other relevant files

.
├── layout.py                              # for drawing things related to 2D hypercube layout
├── test_degeneracy.py                     # test if strict FT is violated in preparation simulations
├── utils.py                               # ancilla residual error loader
└── src                   
    ├── Decoder
    │   ├── Decoder_polar.cpp              # C++ SCL decoder
    │   └── PyDecoder_polar.pyx            # Cython binding for decoder
    └── Simulation         
        └── Simulation_RM127.cpp           # data qubit noise decoding