loom_rotated_surface_code.applicator.shrink

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loom_rotated_surface_code.applicator.shrink.shrink(interpretation_step, operation, same_timeslice, debug_mode)[source]

Shrink a Block in the specified direction.

The algorithm is the following:

  • A.) DATA QUBITS

    • A.1) Find data qubits which are measured in the shrink

  • B.) CIRCUIT

    • B.1) Create classical channels for all data qubit measurements

    • B.2) Create a measurement circuit for every measured data qubit

    • B.3) Append the measurement circuits to the InterpretationStep circuit. If needed, apply a basis change

  • C.) STABILIZERS

    • C.1) Find stabilizers which are completely removed

    • C.2) Find stabilizers which have to be reduced in weight

    • C.3) Create new stabilizers with reduced weight

    • C.4) Update stabilizer_evolution and stabilizer_updates for the stabilizers which have been reduced in weight

    • C.5) Combine the stabilizers to get a new set of stabilizers

    • C.6) Create syndromes for fully measured stabilizers

    • C.7) Create detectors for fully measured stabilizers

  • D.) LOGICAL OPERATORS

    • D.1) Find logical operators which do not have to be modified

  • E.) NEW BLOCK AND NEW INTERPRETATION STEP

    • E.1) Update the stabilizer to circuit mapping

    • E.2) Create the new block

    • E.3) Update the block history

Parameters:

  • interpretation_step (InterpretationStep) – Interpretation step containing the block to shrink.

  • operation (Shrink) – Shrink operation description.

  • same_timeslice (bool) – Flag indicating whether the operation is part of the same timestep as the previous operation.

  • debug_mode (bool) – Flag indicating whether the interpretation should be done in debug mode. Activating debug mode will enable commutation validation for Block

Returns:

Interpretation step after the shrink operation.

Return type:

InterpretationStep

loom_rotated_surface_code.applicator.shrink.shrink_consistency_checks(interpretation_step, operation)[source]

Check if the Shrink operation is valid for the given state of blocks

Parameters:

  • interpretation_step (InterpretationStep) – Interpretation step containing the block to shrink.

  • operation (Shrink) – Shrink operation description.

Returns:

The block to be shrunk.

Return type:

RotatedSurfaceCode