---
title: LitinskiTransformation (latest version)
description: API reference for qiskit.transpiler.passes.LitinskiTransformation in the latest version of qiskit
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/qiskit.transpiler.passes.LitinskiTransformation
---

# LitinskiTransformation

*class* `qiskit.transpiler.passes.LitinskiTransformation(*args, **kwargs)`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.5/qiskit/transpiler/passes/optimization/litinski_transformation.py#L21-L137)

Bases: [`TransformationPass`](/docs/api/qiskit/qiskit.transpiler.TransformationPass "qiskit.transpiler.basepasses.TransformationPass")

Applies Litinski transform to a circuit.

The transform applies to a circuit containing Clifford, single-qubit $R_Z$-rotation, $R_X$-rotation and $R_Y$-rotation gates, (including $Phase$, $T$ and $T^\dagger$), Pauli product rotations, Pauli product measurements, and standard $Z$-measurements. The transform moves Clifford gates to the end of the circuit, including single-qubit rotation gates, Pauli product rotations and Pauli product measurements, whose angle is a multiple of $\pi/2$. In the process, it transforms $R_Z$-rotations, $R_X$-rotation and $R_Y$-rotation gates to Pauli product rotations, and $Z$-measurements to Pauli product measurements.

The pass supports all of the Clifford gates in the list returned by [`get_clifford_gate_names()`](/docs/api/qiskit/qiskit.quantum_info.get_clifford_gate_names "qiskit.quantum_info.get_clifford_gate_names"):

`["id", "x", "y", "z", "h", "s", "sdg", "sx", "sxdg", "cx", "cz", "cy", "swap","iswap", "ecr", "dcx"]`

In addition, the rotation gates above with angles that are integral multiples of $\pi/2$ within the given tolerance are also considered Clifford.

Example:

```python
from qiskit import generate_preset_pass_manager
from qiskit.circuit import QuantumCircuit
from qiskit.circuit.library import PauliProductMeasurement, PauliProductRotationGate
from qiskit.quantum_info import Pauli
from qiskit.transpiler.passes import LitinskiTransformation

litinski = LitinskiTransformation(fix_clifford=False, use_ppr=True)

rz_basis = ["rz", "h", "x", "cx"]
pm = generate_preset_pass_manager(basis_gates=rz_basis)
pm.optimization.append(litinski)

qc = QuantumCircuit(3, 1)
qc.h(0)
qc.rz(1.23, 0)
qc.cx(0, 1)
qc.t(1)
qc.append(PauliProductRotationGate(Pauli("XY"), 0.456), [1, 2])
qc.cx(1, 2)
qc.append(PauliProductMeasurement(Pauli("ZX")), [0, 1], [0])
qc.measure(2, 0)


pbc = pm.run(qc)
```

References:

\[1] Litinski. A Game of Surface Codes. [Quantum 3, 128 (2019)](https://quantum-journal.org/papers/q-2019-03-05-128)

**Parameters**

- **fix\_clifford** – If `False` (non-default), the returned circuit contains only `PauliEvolution` gates, with the final Clifford gates omitted. Note that in this case the operators of the original and synthesized circuits will generally not be equivalent.
- **insert\_barrier** – If `True` and `fix_clifford=True`, insert a barrier between the circuit and the final cliffords. This argument has no effect if `fix_clifford=False`.
- **use\_ppr** – If `True`, use [`PauliProductRotationGate`](/docs/api/qiskit/qiskit.circuit.library.PauliProductRotationGate "qiskit.circuit.library.PauliProductRotationGate") to represent the Pauli rotation gates. This is encouraged to improve performance using a fully Rust-backed path. If `False` or `None`, use [`PauliEvolutionGate`](/docs/api/qiskit/qiskit.circuit.library.PauliEvolutionGate "qiskit.circuit.library.PauliEvolutionGate").
- **approximation\_degree** – Used in the tolerance computations, to check how much a PPR or a rotation gate is close to a Clifford. This gives the threshold for the average gate fidelity.

## 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)`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.5/qiskit/transpiler/basepasses.py#L162-L181)

Execute optimization task for input Qiskit IR.

**Parameters**

- **passmanager\_ir** ([*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit")) – Qiskit IR to optimize.
- **state** ([*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit")) – State associated with workflow execution by the pass manager itself.
- **callback** ([*Callable*](https://docs.python.org/3/library/collections.abc.html#collections.abc.Callable)*\[\[*[*Task*](/docs/api/qiskit/qiskit.passmanager.Task "qiskit.passmanager.base_tasks.Task")*,* [*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit")*,* [*PropertySet*](/docs/api/qiskit/qiskit.passmanager.PropertySet "qiskit.passmanager.compilation_status.PropertySet")*,* [*float*](https://docs.python.org/3/library/functions.html#float)*,* [*int*](https://docs.python.org/3/library/functions.html#int)*], None] | None*) – A callback function which is called per execution of optimization task.

**Returns**

Optimized Qiskit IR and state of the workflow.

**Return type**

[tuple](https://docs.python.org/3/library/stdtypes.html#tuple)\[[*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit"), [*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState "qiskit.passmanager.compilation_status.PassManagerState")]

### name

`name()`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.5/qiskit/passmanager/base_tasks.py#L72-L74)

Name of the pass.

**Return type**

[str](https://docs.python.org/3/library/stdtypes.html#str)

### run

`run(dag)`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.5/qiskit/transpiler/passes/optimization/litinski_transformation.py#L117-L137)

Run the LitinskiTransformation pass on `dag`.

**Parameters**

**dag** ([*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit")) – The input DAG.

**Returns**

The output DAG.

**Raises**

[**TranspilerError**](/docs/api/qiskit/transpiler#qiskit.transpiler.TranspilerError "qiskit.transpiler.TranspilerError") – If the circuit contains gates not supported by the pass.

**Return type**

[*DAGCircuit*](/docs/api/qiskit/qiskit.dagcircuit.DAGCircuit "qiskit._accelerate.circuit.DAGCircuit")

### update\_status

`update_status(state, run_state)`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.5/qiskit/transpiler/basepasses.py#L183-L191)

Update workflow status.

**Parameters**

- **state** ([*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState "qiskit.passmanager.compilation_status.PassManagerState")) – Pass manager state to update.
- **run\_state** (*RunState*) – Completion status of current task.

**Returns**

Updated pass manager state.

**Return type**

[*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState "qiskit.passmanager.compilation_status.PassManagerState")