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GateDirection

qiskit.transpiler.passes.GateDirection(*args, **kwargs)GitHub(opens in a new tab)

Bases: TransformationPass

Modify asymmetric gates to match the hardware coupling direction.

This pass makes use of the following identities:

                     ┌───┐┌───┐┌───┐
q_0: ──■──      q_0: ┤ H ├┤ X ├┤ H ├
     ┌─┴─┐  =        ├───┤└─┬─┘├───┤
q_1: ┤ X ├      q_1: ┤ H ├──■──┤ H ├
     └───┘           └───┘     └───┘
 
 
                  global phase:/2
     ┌──────┐           ┌───┐ ┌────┐┌─────┐┌──────┐┌───┐
q_0:0     ├     q_0: ─┤ S ├─┤ √X ├┤ Sdg ├┤1     ├┤ H ├
     │  ECR │  =       ┌┴───┴┐├────┤└┬───┬┘│  Ecr │├───┤
q_1:1     ├     q_1: ┤ Sdg ├┤ √X ├─┤ S ├─┤0     ├┤ H ├
     └──────┘          └─────┘└────┘ └───┘ └──────┘└───┘
 
 
     ┌──────┐          ┌───┐┌──────┐┌───┐
q_0:0     ├     q_0: ┤ H ├┤1     ├┤ H ├
     │  RZX │  =       ├───┤│  RZX │├───┤
q_1:1     ├     q_1: ┤ H ├┤0     ├┤ H ├
     └──────┘          └───┘└──────┘└───┘

This pass assumes that the positions of the qubits in the DAGCircuit.qubits attribute are the physical qubit indicies. For example if dag.qubits[0] is qubit 0 in the CouplingMap or Target.

GateDirection pass.

Parameters

  • coupling_map (CouplingMap) – Directed graph represented a coupling map.
  • target (Target) – The backend target to use for this pass. If this is specified it will be used instead of the coupling map

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).


Methods

execute

execute(passmanager_ir, state, callback=None)

Execute optimization task for input Qiskit IR.

Parameters

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]

name

name()

Name of the pass.

Return type

str(opens in a new tab)

run

run(dag)

Run the GateDirection pass on dag.

Flips the cx nodes to match the directed coupling map. Modifies the input dag.

Parameters

dag (DAGCircuit) – DAG to map.

Returns

The rearranged dag for the coupling map

Return type

DAGCircuit

Raises

TranspilerError – If the circuit cannot be mapped just by flipping the cx nodes.

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

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