NLocal¶

class NLocal(num_qubits=None, rotation_blocks=None, entanglement_blocks=None, entanglement=None, reps=1, insert_barriers=False, parameter_prefix='θ', overwrite_block_parameters=True, skip_final_rotation_layer=False, skip_unentangled_qubits=False, initial_state=None, name='nlocal')[código fonte]¶

Bases: BlueprintCircuit

The n-local circuit class.

The structure of the n-local circuit are alternating rotation and entanglement layers. In both layers, parameterized circuit-blocks act on the circuit in a defined way. In the rotation layer, the blocks are applied stacked on top of each other, while in the entanglement layer according to the entanglement strategy. The circuit blocks can have arbitrary sizes (smaller equal to the number of qubits in the circuit). Each layer is repeated reps times, and by default a final rotation layer is appended.

For instance, a rotation block on 2 qubits and an entanglement block on 4 qubits using 'linear' entanglement yields the following circuit.

┌──────┐ ░ ┌──────┐                      ░ ┌──────┐
┤0     ├─░─┤0     ├──────────────── ... ─░─┤0     ├
│  Rot │ ░ │      │┌──────┐              ░ │  Rot │
┤1     ├─░─┤1     ├┤0     ├──────── ... ─░─┤1     ├
├──────┤ ░ │  Ent ││      │┌──────┐      ░ ├──────┤
┤0     ├─░─┤2     ├┤1     ├┤0     ├ ... ─░─┤0     ├
│  Rot │ ░ │      ││  Ent ││      │      ░ │  Rot │
┤1     ├─░─┤3     ├┤2     ├┤1     ├ ... ─░─┤1     ├
├──────┤ ░ └──────┘│      ││  Ent │      ░ ├──────┤
┤0     ├─░─────────┤3     ├┤2     ├ ... ─░─┤0     ├
│  Rot │ ░         └──────┘│      │      ░ │  Rot │
┤1     ├─░─────────────────┤3     ├ ... ─░─┤1     ├
└──────┘ ░                 └──────┘      ░ └──────┘

|                                 |
+---------------------------------+
       repeated reps times

If specified, barriers can be inserted in between every block. If an initial state object of Qiskit Aqua is provided, it is added in front of the NLocal.

Create a new n-local circuit.

Parâmetros

num_qubits (Optional[int]) – The number of qubits of the circuit.
rotation_blocks (Union[QuantumCircuit, List[QuantumCircuit], Instruction, List[Instruction], None]) – The blocks used in the rotation layers. If multiple are passed, these will be applied one after another (like new sub-layers).
entanglement_blocks (Union[QuantumCircuit, List[QuantumCircuit], Instruction, List[Instruction], None]) – The blocks used in the entanglement layers. If multiple are passed, these will be applied one after another. To use different entanglements for the sub-layers, see get_entangler_map().
entanglement (Union[List[int], List[List[int]], None]) – The indices specifying on which qubits the input blocks act. If None, the entanglement blocks are applied at the top of the circuit.
reps (int) – Specifies how often the rotation blocks and entanglement blocks are repeated.
insert_barriers (bool) – If True, barriers are inserted in between each layer. If False, no barriers are inserted.
parameter_prefix (str) – The prefix used if default parameters are generated.
overwrite_block_parameters (Union[bool, List[List[Parameter]]]) – If the parameters in the added blocks should be overwritten. If False, the parameters in the blocks are not changed.
skip_final_rotation_layer (bool) – Whether a final rotation layer is added to the circuit.
skip_unentangled_qubits (bool) – If True, the rotation gates act only on qubits that are entangled. If False, the rotation gates act on all qubits.
initial_state (Optional[Any]) – A QuantumCircuit object which can be used to describe an initial state prepended to the NLocal circuit.
name (Optional[str]) – The name of the circuit.

Examples

TODO

Levanta

ImportError – If an initial_state is specified but Qiskit Aqua is not installed.
ValueError – If reps parameter is less than or equal to 0.
TypeError – If reps parameter is not an int value.

Methods Defined Here

`add_layer`	Append another layer to the NLocal.
`assign_parameters`	Assign parameters to the n-local circuit.
`get_entangler_map`	Get the entangler map for in the repetition `rep_num` and the block `block_num`.
`get_unentangled_qubits`	Get the indices of unentangled qubits in a set.
`print_settings`	Returns information about the setting.

Attributes

ancillas¶

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

Tipo de retorno: List[AncillaQubit]

calibrations¶

Return calibration dictionary.

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

Tipo de retorno: dict

clbits¶

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

Tipo de retorno: List[Clbit]

data¶

entanglement¶

Get the entanglement strategy.

Tipo de retorno: Union[str, List[str], List[List[str]], List[int], List[List[int]], List[List[List[int]]], List[List[List[List[int]]]], Callable[[int], str], Callable[[int], List[List[int]]]]
Retorno: The entanglement strategy, see get_entangler_map() for more detail on how the format is interpreted.

entanglement_blocks¶

The blocks in the entanglement layers.

Tipo de retorno: List[Instruction]
Retorno: The blocks in the entanglement layers.

extension_lib = 'include "qelib1.inc";'¶

global_phase¶

Return the global phase of the circuit in radians.

Tipo de retorno: Union[ParameterExpression, float]

header = 'OPENQASM 2.0;'¶

initial_state¶

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

Tipo de retorno: Any
Retorno: The initial state.

insert_barriers¶

If barriers are inserted in between the layers or not.

Tipo de retorno: bool
Retorno: True, if barriers are inserted in between the layers, False if not.

instances = 94¶

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.

Tipo de retorno: dict

num_ancillas¶

Return the number of ancilla qubits.

Tipo de retorno: int

num_clbits¶

Return number of classical bits.

Tipo de retorno: int

num_layers¶

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

Tipo de retorno: int
Retorno: The number of layers in the circuit.

num_parameters¶

Tipo de retorno: int

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.

Tipo de retorno: int
Retorno: The number of parameters originally available in the circuit.

Nota

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

num_qubits¶

Returns the number of qubits in this circuit.

Tipo de retorno: int
Retorno: The number of 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.

Tipo de retorno: List[int]
Retorno: List of integers representing instruction start times. The index corresponds to the index of instruction in QuantumCircuit.data.
Levanta: AttributeError – When circuit is not scheduled.

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])]

Tipo de retorno: List[Parameter]
Retorno: The parameters objects used in the circuit.

parameter_bounds¶

The parameter bounds for the unbound parameters in the circuit.

Tipo de retorno: Optional[List[Tuple[float, float]]]
Retorno: 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¶

Tipo de retorno: ParameterView

preferred_init_points¶

The initial points for the parameters. Can be stored as initial guess in optimization.

Tipo de retorno: Optional[List[float]]
Retorno: The initial values for the parameters, or None, if none have been set.

prefix = '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.

Tipo de retorno: List[Qubit]

reps¶

The number of times rotation and entanglement block are repeated.

Tipo de retorno: int
Retorno: The number of repetitions.

rotation_blocks¶

The blocks in the rotation layers.

Tipo de retorno: List[Instruction]
Retorno: The blocks in the rotation layers.