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RZXCalibrationBuilder

RZXCalibrationBuilder(backend=None, instruction_schedule_map=None, qubit_channel_mapping=None) GitHub(opens in a new tab)

Bases: qiskit.transpiler.passes.calibration.builders.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

  • backend (Union[BaseBackend, BackendV1, None]) – DEPRECATED a backend object to build the calibrations for. Use of this argument is deprecated in favor of directly specifying instruction_schedule_map and qubit_channel_map.
  • instruction_schedule_map (Optional[InstructionScheduleMap]) – The InstructionScheduleMap object representing the default pulse calibrations for the target backend
  • qubit_channel_mapping (Optional[List[List[str]]]) – The list mapping qubit indices to the list of channel names that apply on that qubit.

Raises

QiskitError – if open pulse is not supported by the backend.


Methods

get_calibration

RZXCalibrationBuilder.get_calibration(node_op, qubits)

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

Parameters

  • node_op (Instruction) – Instruction of the RZXGate(theta). I.e. params[0] is theta.
  • qubits (List) – 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 the control and target qubits cannot be identified or the backend does not support cx between the qubits.

name

RZXCalibrationBuilder.name()

Return the name of the pass.

rescale_cr_inst

static RZXCalibrationBuilder.rescale_cr_inst(instruction, theta, sample_mult=16)

Parameters

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

Returns

The play instruction with the stretched compressed

GaussianSquare pulse.

Return type

qiskit.pulse.Play

Raises

QiskitError – if the pulses are not GaussianSquare.

run

RZXCalibrationBuilder.run(dag)

Run the calibration adder pass on dag.

Parameters

dag (DAGCircuit) – DAG to schedule.

Return type

DAGCircuit

Returns

A DAG with calibrations added to it.

supported

RZXCalibrationBuilder.supported(node_op, qubits)

Determine if a given node supports the calibration.

Parameters

  • node_op (Instruction) – Target instruction object.
  • qubits (List) – Integer qubit indices to check.

Return type

bool

Returns

Return True is calibration can be provided.


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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