EvolvedOperatorAnsatz

class qiskit.circuit.library.EvolvedOperatorAnsatz(operators=None, reps=1, evolution=None, insert_barriers=False, name='EvolvedOps', parameter_prefix='t', initial_state=None, flatten=None)

Bases: NLocal

The evolved operator ansatz.

Parameters:

• operators (BaseOperator | OperatorBase | QuantumCircuit | list | None) -- The operators to evolve. If a circuit is passed, we assume it implements an already evolved operator and thus the circuit is not evolved again. Can be a single operator (circuit) or a list of operators (and circuits).

• reps (int) -- The number of times to repeat the evolved operators.

• evolution (EvolutionBase | EvolutionSynthesis | None) -- A specification of which evolution synthesis to use for the PauliEvolutionGate, if the operator is from qiskit.quantum_info or an opflow converter object if the operator is from qiskit.opflow. Defaults to first order Trotterization.

• insert_barriers (bool) -- Whether to insert barriers in between each evolution.

• name (str) -- The name of the circuit.

• parameter_prefix (str | Sequence[str]) -- Set the names of the circuit parameters. If a string, the same prefix will be used for each parameters. Can also be a list to specify a prefix per operator.

• initial_state (QuantumCircuit | None) -- A QuantumCircuit object to prepend to the circuit.

• flatten (bool | None) -- Set this to True to output a flat circuit instead of nesting it inside multiple layers of gate objects. By default currently the contents of the output circuit will be wrapped in nested objects for cleaner visualization. However, if you're using this circuit for anything besides visualization its strongly recommended to set this flag to True to avoid a large performance overhead for parameter binding.

Attributes

ancillas

Returns a list of ancilla bits in the order that the registers were added.

calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form {'gate_name': {(qubits, params): schedule}}

clbits

Returns a list of classical bits in the order that the registers were added.

data

entanglement

Get the entanglement strategy.

Returns:

The entanglement strategy, see get_entangler_map() for more detail on how the format is interpreted.

entanglement_blocks

The blocks in the entanglement layers.

Returns:

The blocks in the entanglement layers.

evolution

The evolution converter used to compute the evolution.

Returns:

The evolution converter used to compute the evolution.

Return type:

EvolutionBase or EvolutionSynthesis

extension_lib = 'include "qelib1.inc";'

flatten

Returns whether the circuit is wrapped in nested gates/instructions or flattened.

global_phase

Return the global phase of the circuit in radians.

header = 'OPENQASM 2.0;'

initial_state

Return the initial state that is added in front of the n-local circuit.

Returns:

The initial state.

insert_barriers

If barriers are inserted in between the layers or not.

Returns:

True, if barriers are inserted in between the layers, False if not.

instances = 127

layout

Return any associated layout information about the circuit

This attribute contains an optional TranspileLayout object. This is typically set on the output from transpile() or PassManager.run() to retain information about the permutations caused on the input circuit by transpilation.

There are two types of permutations caused by the transpile() function, an initial layout which permutes the qubits based on the selected physical qubits on the Target, and a final layout which is an output permutation caused by SwapGates inserted during routing.

metadata

The user provided metadata associated with the circuit.

The metadata for the circuit is a user provided dict of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.

num_ancillas

Return the number of ancilla qubits.

num_clbits

Return number of classical bits.

num_layers

Return the number of layers in the n-local circuit.

Returns:

The number of layers in the circuit.

num_parameters

num_parameters_settable

The number of total parameters that can be set to distinct values.

This does not change when the parameters are bound or exchanged for same parameters, and therefore is different from num_parameters which counts the number of unique Parameter objects currently in the circuit.

Returns:

The number of parameters originally available in the circuit.

Note

This quantity does not require the circuit to be built yet.

num_qubits

op_start_times

Return a list of operation start times.

This attribute is enabled once one of scheduling analysis passes runs on the quantum circuit.

Returns:

List of integers representing instruction start times. The index corresponds to the index of instruction in QuantumCircuit.data.

Raises:

AttributeError -- When circuit is not scheduled.

operators

The operators that are evolved in this circuit.

Returns:

The operators to be evolved (and circuits) contained in this ansatz.

Return type:

list

ordered_parameters

The parameters used in the underlying circuit.

This includes float values and duplicates.

Examples

>>> # prepare circuit ...
>>> print(nlocal)
     ┌───────┐┌──────────┐┌──────────┐┌──────────┐
q_0: ┤ Ry(1) ├┤ Ry(θ[1]) ├┤ Ry(θ[1]) ├┤ Ry(θ[3]) ├
     └───────┘└──────────┘└──────────┘└──────────┘
>>> nlocal.parameters
{Parameter(θ[1]), Parameter(θ[3])}
>>> nlocal.ordered_parameters
[1, Parameter(θ[1]), Parameter(θ[1]), Parameter(θ[3])]

Returns:

The parameters objects used in the circuit.

parameter_bounds

The parameter bounds for the unbound parameters in the circuit.

Returns:

A list of pairs indicating the bounds, as (lower, upper). None indicates an unbounded parameter in the corresponding direction. If None is returned, problem is fully unbounded.

parameters

preferred_init_points

Getter of preferred initial points based on the given initial state.

prefix = 'circuit'

qregs: list[QuantumRegister]

A list of the quantum registers associated with the circuit.

qubits

Returns a list of quantum bits in the order that the registers were added.

reps

The number of times rotation and entanglement block are repeated.

Returns:

The number of repetitions.

rotation_blocks

The blocks in the rotation layers.

Returns:

The blocks in the rotation layers.