qiskit.circuit.library.PauliEvolutionGate(operator, time=1.0, label=None, synthesis=None)
Time-evolution of an operator consisting of Paulis.
For an operator consisting of Pauli terms and (real) evolution time this gate implements
This gate serves as a high-level definition of the evolution and can be synthesized into a circuit using different algorithms.
The evolution gates are related to the Pauli rotation gates by a factor of 2. For example the time evolution of the Pauli operator is connected to the Pauli rotation by
from qiskit.circuit import QuantumCircuit from qiskit.circuit.library import PauliEvolutionGate from qiskit.opflow import I, Z, X # build the evolution gate operator = (Z ^ Z) - 0.1 * (X ^ I) evo = PauliEvolutionGate(operator, time=0.2) # plug it into a circuit circuit = QuantumCircuit(2) circuit.append(evo, range(2)) print(circuit.draw())
The above will print (note that the
-0.1 coefficient is not printed!):
┌──────────────────────────┐ q_0: ┤0 ├ │ exp(-it (ZZ + XI))(0.2) │ q_1: ┤1 ├ └──────────────────────────┘
 G. Li et al. Paulihedral: A Generalized Block-Wise Compiler Optimization Framework For Quantum Simulation Kernels (2021). [arXiv:2109.03371 (opens in a new tab)]
- operator (Pauli |PauliOp |SparsePauliOp |PauliSumOp |list (opens in a new tab)) – The operator to evolve. Can also be provided as list of non-commuting operators where the elements are sums of commuting operators. For example:
[XY + YX, ZZ + ZI + IZ, YY].
- time (Union[int (opens in a new tab), float (opens in a new tab), ParameterExpression]) – The evolution time.
- label (Optional[str (opens in a new tab)]) – A label for the gate to display in visualizations. Per default, the label is set to
<operators>is the sum of the Paulis. Note that the label does not include any coefficients of the Paulis. See the class docstring for an example.
- synthesis (Optional[EvolutionSynthesis]) – A synthesis strategy. If None, the default synthesis is the Lie-Trotter product formula with a single repetition.
Get the base class of this instruction. This is guaranteed to be in the inheritance tree of
The “base class” of an instruction is the lowest class in its inheritance tree that the object should be considered entirely compatible with for _all_ circuit applications. This typically means that the subclass is defined purely to offer some sort of programmer convenience over the base class, and the base class is the “true” class for a behavioural perspective. In particular, you should not override
base_class if you are defining a custom version of an instruction that will be implemented differently by hardware, such as an alternative measurement strategy, or a version of a parametrised gate with a particular set of parameters for the purposes of distinguishing it in a
Target from the full parametrised gate.
This is often exactly equivalent to
type(obj), except in the case of singleton instances of standard-library instructions. These singleton instances are special subclasses of their base class, and this property will return that base. For example:
>>> isinstance(XGate(), XGate) True >>> type(XGate()) is XGate False >>> XGate().base_class is XGate True
In general, you should not rely on the precise class of an instruction; within a given circuit, it is expected that
Instruction.name should be a more suitable discriminator in most situations.
The classical condition on the instruction.
Get Clbits in condition.
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
Return definition in terms of other basic gates.
Get the duration.
Return instruction label
Is this instance is a mutable unique instance or not.
If this attribute is
False the gate instance is a shared singleton and is not mutable.
Return the name.
Return the number of clbits.
Return the number of qubits.
return instruction params.
Return the evolution time as stored in the gate parameters.
The evolution time.
Get the time unit of duration.
Gate parameters should be int, float, or ParameterExpression