RZXCalibrationBuilder

qiskit.transpiler.passes.RZXCalibrationBuilder(*args, **kwargs)

Bases: CalibrationBuilder

Creates calibrations for RZXGate(theta) by stretching and compressing Gaussian square pulses in the CX gate. This is done by retrieving (for a given pair of qubits) the CX schedule in the instruction schedule map of the backend defaults. The CX schedule must be an echoed cross-resonance gate optionally with rotary tones. The cross-resonance drive tones and rotary pulses must be Gaussian square pulses. The width of the Gaussian square pulse is adjusted so as to match the desired rotation angle. If the rotation angle is small such that the width disappears then the amplitude of the zero width Gaussian square pulse (i.e. a Gaussian) is reduced to reach the target rotation angle. Additional details can be found in https://arxiv.org/abs/2012.11660 (opens in a new tab).

Initializes a RZXGate calibration builder.

Parameters

• instruction_schedule_map – The InstructionScheduleMap object representing the default pulse calibrations for the target backend
• verbose – Set True to raise a user warning when RZX schedule cannot be built.
• target – The Target representing the target backend, if both instruction_schedule_map and this are specified then this argument will take precedence and instruction_schedule_map will be ignored.

Raises

QiskitError – Instruction schedule map is not provided.

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Attributes

is_analysis_pass

Check if the pass is an analysis pass.

If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.

is_transformation_pass

Check if the pass is a transformation pass.

If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).

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Methods

execute

execute(passmanager_ir, state, callback=None)

Execute optimization task for input Qiskit IR.

Parameters

• passmanager_ir (Any (opens in a new tab)) – Qiskit IR to optimize.
• state (PassManagerState) – State associated with workflow execution by the pass manager itself.
• callback (Callable (opens in a new tab) | None) – A callback function which is caller per execution of optimization task.

Returns

Optimized Qiskit IR and state of the workflow.

Return type

tuple (opens in a new tab)[Any (opens in a new tab), qiskit.passmanager.compilation_status.PassManagerState]

get_calibration

get_calibration(node_op, qubits)

Builds the calibration schedule for the RZXGate(theta) with echos.

Parameters

• node_op (CircuitInst) – Instruction of the RZXGate(theta). I.e. params[0] is theta.
• qubits (list (opens in a new tab)) – List of qubits for which to get the schedules. The first qubit is the control and the second is the target.

Returns

The calibration schedule for the RZXGate(theta).

Return type

schedule

Raises

• QiskitError – if rotation angle is not assigned.
• QiskitError – If the control and target qubits cannot be identified.
• CalibrationNotAvailable – RZX schedule cannot be built for input node.

name

name()

Name of the pass.

Return type

str (opens in a new tab)

rescale_cr_inst

static rescale_cr_inst(instruction, theta, sample_mult=16)

A builder macro to play stretched pulse.

Parameters

• instruction (Play) – The instruction from which to create a new shortened or lengthened pulse.
• theta (float (opens in a new tab)) – desired angle, pi/2 is assumed to be the angle that the pulse in the given play instruction implements.
• sample_mult (int (opens in a new tab)) – All pulses must be a multiple of sample_mult.

Returns

Duration of stretched pulse.

Raises

QiskitError – if rotation angle is not assigned.

Return type

int (opens in a new tab)

run

run(dag)

Run the calibration adder pass on dag.

Parameters

dag (DAGCircuit) – DAG to schedule.

Returns

A DAG with calibrations added to it.

Return type

DAGCircuit

supported

supported(node_op, qubits)

Determine if a given node supports the calibration.

Parameters

• node_op (Instruction) – Target instruction object.
• qubits (list (opens in a new tab)) – Integer qubit indices to check.

Returns

Return True is calibration can be provided.

Return type

bool (opens in a new tab)

update_status

update_status(state, run_state)

Update workflow status.

Parameters

• state (PassManagerState) – Pass manager state to update.
• run_state (RunState) – Completion status of current task.

Returns

Updated pass manager state.

Return type

PassManagerState