QAOAAnsatz
class QAOAAnsatz(cost_operator=None, reps=1, initial_state=None, mixer_operator=None, name='QAOA')
Bases: qiskit.circuit.library.evolved_operator_ansatz.EvolvedOperatorAnsatz
A generalized QAOA quantum circuit with a support of custom initial states and mixers.
References
[1]: Farhi et al., A Quantum Approximate Optimization Algorithm.
Parameters
- cost_operator (OperatorBase, optional) – The operator representing the cost of the optimization problem, denoted as in the original paper. Must be set either in the constructor or via property setter.
- reps (int) – The integer parameter p, which determines the depth of the circuit, as specified in the original paper, default is 1.
- initial_state (QuantumCircuit, optional) – An optional initial state to use. If None is passed then a set of Hadamard gates is applied as an initial state to all qubits.
- mixer_operator (OperatorBase orQuantumCircuit, optional) – An optional custom mixer to use instead of the global X-rotations, denoted as in the original paper. Can be an operator or an optionally parameterized quantum circuit.
- name (str) – A name of the circuit, default ‘qaoa’
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.
cost_operator
Returns an operator representing the cost of the optimization problem.
Returns
cost operator.
Return type
data
evolution
The evolution converter used to compute the evolution.
Returns
The evolution converter used to compute the evolution.
Return type
extension_lib
Default value: 'include "qelib1.inc";'
global_phase
Return the global phase of the circuit in radians.
header
Default value: 'OPENQASM 2.0;'
initial_state
Returns an optional initial state as a circuit
Return type
Optional[QuantumCircuit]
instances
Default value: 16
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.
mixer_operator
Returns an optional mixer operator expressed as an operator or a quantum circuit.
Returns
mixer operator or circuit.
Return type
OperatorBase or QuantumCircuit, optional
num_ancillas
Return the number of ancilla qubits.
num_clbits
Return number of classical bits.
num_parameters
Return type
int
num_qubits
Return the number of qubits, specified by the size of the cost operator.
Return type
int
operators
The operators that are evolved in this circuit.
Returns
The operators to be evolved (and circuits)
in this ansatz.
Return type
List[Union[OperatorBase, QuantumCircuit]]
parameter_bounds
Parameter bounds.
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 or is not built yet.
Return type
List[Tuple[float, float]]
parameters
Get the Parameter objects in the circuit.
Return type
Set[Parameter]
Returns
A set containing the unbound circuit parameters.
preferred_init_points
Getter of preferred initial points based on the given initial state.
prefix
Default value: 'circuit'
qregs
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
Returns the reps parameter, which determines the depth of the circuit.
Return type
int