heavy_hex.jl

HeavyHexParameters

Parameters for the syndrome extraction circuit of a heavy hex code.

Fields

• params::Dict{Symbol, Any}: Dictionary of the circuit parameters described below.
• circuit_name::String: Name of the circuit used for saving data.

Parameters

• vertical_dist::Int: Vertical (Z) distance of the code.
• horizontal_dist::Int: Horizontal (X) distance of the code.
• flipped::Bool: Whether ancilla qubit layout is flipped left to right.
• gate_type::Symbol: Type of two-qubit gate used in the circuit, which must be :cx.
• ancilla_measurement::Bool: Whether to include mid-circuit ancilla measurements.
• pad_identity::Bool: Whether to pad layers with single-qubit identity gates.
• layer_time_dict::Dict{Symbol, Float64}: Dictionary of layer times.

get_circuit(hex_param::HeavyHexParameters, noise_param::AbstractNoiseParameters; kwargs...)

Returns a heavy hex code syndrome extraction circuit in the form of a Circuit object parameterised by the supplied circuit and noise parameters.

Arguments

• hex_param::HeavyHexParameters: Parameters for a heavy hex code.
• noise_param::AbstractNoiseParameters: Noise parameters for the circuit.

Keyword arguments

• noisy_prep::Bool = false: Whether to treat preparations as noisy and characterise the associated noise, defaulting to false; a full-rank design cannot be produced if both noisy_prep and noisy_meas are true.
• noisy_meas::Bool = true: Whether to treat measurements as noisy and characterise the associated noise, defaulting to true; a full-rank design cannot be produced if both noisy_prep and noisy_meas are true.
• combined::Bool = haskey(noise_param.params, :combined) ? noise_param.params[:combined] : false,: Whether to treat Pauli X, Y, and Z basis SPAM noise as the same.
• strict::Bool = false: Whether to be strict about which gates count as estimable to relative precision.

get_hex_param(vertical_dist::Integer, horizontal_dist::Integer; kwargs...)
get_hex_param(dist::Integer; kwargs...)

Returns a HeavyHexParameters object that parameterises the syndrome extraction circuit of a heavy hex code.

Default gate layer times are estimated from IBM Torino in 2024.

Arguments

• vertical_dist::Int: Vertical distance of the code.
• horizontal_dist::Int: Horizontal distance of the code.
• dist::Int: Distance of the code; this is equivalent to setting vertical_dist = dist and horizontal_dist = dist.

Keyword arguments

• flipped::Bool = false: Whether to flip the ancilla qubit layout left to right.
• gate_type::Symbol = :cx: Type of two-qubit gate used in the circuit.
• ancilla_measurement::Bool = true: Whether to include mid-circuit reset.
• pad_identity::Bool = true: Whether to pad layers with single-qubit identity gates.
• single_qubit_time::Real = 32: Time taken to implement a single-qubit gate in nanoseconds.
• two_qubit_time::Real = 200: Time taken to implement a two-qubit gate in nanoseconds.
• meas_reset_time::Real = 2500: Time taken to perform measurement and reset at the end of the circuit in nanoseconds.
• meas_reset_time::Real = 2500: Time taken to perform mid-circuit reset in nanoseconds.

heavy_hex_circuit(hex_param::HeavyHexParameters)

Returns fields used to construct the syndrome extraction circuit of a heavy hex code based on the supplied parameters hex_param.