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')

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 is provided, it is added in front of the NLocal.

Create a new n-local circuit.

Parâmetros

• num_qubits (int | None) – The number of qubits of the circuit.

• rotation_blocks (QuantumCircuit | list[QuantumCircuit] | qiskit.circuit.Instruction | list[qiskit.circuit.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 (QuantumCircuit | list[QuantumCircuit] | qiskit.circuit.Instruction | list[qiskit.circuit.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 (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 (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 (QuantumCircuit | None) – A QuantumCircuit object which can be used to describe an initial state prepended to the NLocal circuit.

• name (str | None) – The name of the circuit.

Examples

TODO

Levanta

• 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.

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.

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.

Retorno

The blocks in the entanglement layers.

extension_lib = 'include "qelib1.inc";'

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.

Retorno

The initial state.

insert_barriers

If barriers are inserted in between the layers or not.

Retorno

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

instances = 209

layout

Return any associated layout information anout 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.

Retorno

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.

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.

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.

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])]

Retorno

The parameters objects used in the circuit.

parameter_bounds

The parameter bounds for the unbound parameters in the circuit.

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

preferred_init_points

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

Retorno

The initial values for the parameters, or None, if none have been set.

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.

Retorno

The number of repetitions.

rotation_blocks

The blocks in the rotation layers.

Retorno

The blocks in the rotation layers.