IntegerComparator

class IntegerComparator(num_state_qubits=None, value=None, geq=True, name='cmp')

Bases: qiskit.circuit.library.blueprintcircuit.BlueprintCircuit

Integer Comparator.

Operator compares basis states \(|i\rangle_n\) against a classically given integer \(L\) of fixed value and flips a target qubit if \(i \geq L\) (or \(<\) depending on the parameter geq):

\[|i\rangle_n |0\rangle \mapsto |i\rangle_n |i \geq L\rangle\]

This operation is based on two’s complement implementation of binary subtraction but only uses carry bits and no actual result bits. If the most significant carry bit (the results bit) is 1, the \(\geq\) condition is True otherwise it is False.

Create a new fixed value comparator circuit.

Parameters

• num_state_qubits (Optional[int]) – Number of state qubits. If this is set it will determine the number of qubits required for the circuit.

• value (Optional[int]) – The fixed value to compare with.

• geq (bool) – If True, evaluate a >= condition, else <.

• name (str) – Name of the circuit.

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

extension_lib = 'include "qelib1.inc";'

geq

Return whether the comparator compares greater or less equal.

Return type

bool

Returns

True, if the comparator compares >=, False if <.

global_phase

Return the global phase of the circuit in radians.

header = 'OPENQASM 2.0;'

instances = 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.

num_ancilla_qubits

Deprecated. Use num_ancillas instead.

num_ancillas

Return the number of ancilla qubits.

num_clbits

Return number of classical bits.

num_parameters

Return type

int

num_qubits

Return number of qubits.

num_state_qubits

The number of qubits encoding the state for the comparison.

Return type

int

Returns

The number of state qubits.

parameters

Return type

ParameterView

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.

value

The value to compare the qubit register to.

Return type

int

Returns

The value against which the value of the qubit register is compared.