loom_rotated_surface_code.applicator.rotate_block

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loom_rotated_surface_code.applicator.rotate_block.get_boundary_rotation_corner_args_5_1(rsc_block)[source]

Rotate the boundaries by using move_corners 5 times, moving 1 corner at a time. The corners are moved in a way such that the distance of the block for all logical operators is at least the original distance, ensuring fault-tolerance. For this to be possible, the block must be of size (d, 2 * d - 1) or (2 * d - 1, d) with odd d.

Parameters:

rsc_block (RotatedSurfaceCode) – The grown rectangular rotated surface code block.

Returns:

A tuple containing 5 tuples, each specifying the arguments for a call to move_corners. Each inner tuple contains:

  • The coordinates of the corner to move (as a tuple of integers).

  • The direction in which to move the corner (as a Direction enum).

  • The distance to move the corner (as an integer).

Return type:

tuple[tuple[tuple[int, …], Direction, int], …]

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

Rotate the boundary of a rotated surface code block by growing it in the specified direction, moving the corners in a fault-tolerant manner and shrinking back to the original size.

The rotation is performed by:

  • A.) Validity checks

    • A.1) Check that the block is a valid RotatedSurfaceCode block for RotateBlock

  • B.) Grow the block in the specified direction

    • B.1) Grow the block to double its size minus one in the specified direction

    • B.2) Measure syndromes to complete the grow operation

    • B.3) Move the logical operators so that they are correctly located on the

      top-left qubit of the grown block

  • C.) Move the corners appropriately

    • C.1) Move each corner individually

    • C.2) Measure syndromes to complete the corner move in a fault-tolerant manner

  • D.) Shrink the block

    • D.1) Shrink the block from the grown side by distance - 2

    • D.2) Shrink the block from the opposite side by 1 to return to original size

  • E.) Move block

    • E.1) Move the block so that it’s occupying the same data qubits as initially

    • E.2) Move the logical operators so that they are correctly located on the

      top-left qubit of the shrunk block

  • F.) Wrap the circuit

    • F.1) Isolate the circuit corresponding to the RotateBlock operation and append

      it as a single Circuit object to the intermediate circuit sequence

Parameters:

  • interpretation_step (InterpretationStep) – The current interpretation step containing the block to be rotated.

  • operation (RotateBlock) – The RotateBlock operation specifying the block and direction.

  • same_timeslice (bool) – Flag to apply the operation in the same timeslice as the previous operation(s).

  • debug_mode (bool) – Flag to apply validation of the new block or not.

Returns:

The updated interpretation step after applying the RotateBlock operation.

Return type:

InterpretationStep

loom_rotated_surface_code.applicator.rotate_block.rotate_validity_check(rsc_block)[source]

Validity checks for applying RotateBlock to a RotatedSurfaceCode block. We check that:

  • The block is indeed a RotatedSurfaceCode block

  • The block is square and has odd distance

  • The topological and geometric corners match