surface_sim.circuit_blocks.unrot_surface_code_css.encoding_qubits_iterator

encoding_qubits_iterator(model, layout, physical_reset_op, primitive_gates, single_layer_resets=False)

Yields stim circuit blocks which as a whole correspond to an encoding circuit to an unrotated surface code of the given model without the detectors. Note that this encoding circuit is not fault tolerant.

Parameters:

model

Noise model for the gates.

layout

Code layout.

physical_reset_op

Reset operation to be applied to the physical qubit that will grow to a unrotated surface code.

primitive_gates

Set of primitive gates to use. The available options are: (1) "cnot", which uses RZ, RX, and CNOT gates, and (2) "cz", which uses RZ, H, and CZ gates. Note that the physical_reset_op will not be decomposed into primitive gates.

single_layer_resets

Flag to put all resets in a single operation layer at the beginning of the encoding circuit. By default False.

Notes

The implementation follows Figures 2 and 9 from:

Higgott, Oscar. “Optimal local unitary encoding circuits for the surface code.” Quantum 5, 517 (2021).