QDrift

class qiskit.synthesis.QDrift(reps=1, insert_barriers=False, cx_structure='chain', atomic_evolution=None, seed=None)[source]

Bases: ProductFormula

The QDrift Trotterization method, which selects each each term in the Trotterization randomly, with a probability proportional to its weight. Based on the work of Earl Campbell in Ref. [1].

References

[1]: E. Campbell, “A random compiler for fast Hamiltonian simulation” (2018). arXiv:quant-ph/1811.08017

Parameters:

  • reps (int) – The number of times to repeat the Trotterization circuit.

  • insert_barriers (bool) – Whether to insert barriers between the atomic evolutions.

  • cx_structure (str) – How to arrange the CX gates for the Pauli evolutions, can be “chain”, where next neighbor connections are used, or “fountain”, where all qubits are connected to one.

  • atomic_evolution (Callable[[Pauli | SparsePauliOp, float], QuantumCircuit] | None) – A function to construct the circuit for the evolution of single Pauli string. Per default, a single Pauli evolution is decomposed in a CX chain and a single qubit Z rotation.

  • seed (int | None) – An optional seed for reproducibility of the random sampling process.

Attributes

settings

Return the settings in a dictionary, which can be used to reconstruct the object.

Returns:

A dictionary containing the settings of this product formula.

Raises:

NotImplementedError – If a custom atomic evolution is set, which cannot be serialized.

Methods

synthesize(evolution)[source]

Synthesize an qiskit.circuit.library.PauliEvolutionGate.

Parameters:

evolution (PauliEvolutionGate) – The evolution gate to synthesize.

Returns:

A circuit implementing the evolution.

Return type:

QuantumCircuit