Bases: Adder

A circuit that uses QFT to perform in-place addition on two qubit registers.

For registers with $$n$$ qubits, the QFT adder can perform addition modulo $$2^n$$ (with kind="fixed") or ordinary addition by adding a carry qubits (with kind="half").

As an example, a non-fixed_point QFT adder circuit that performs addition on two 2-qubit sized registers is as follows:

 a_0:   ─────────■──────■────────────────────────■────────────────
│      │                        │
a_1:   ─────────┼──────┼────────■──────■────────┼────────────────
┌──────┐ │P(π)  │        │      │        │       ┌───────┐
b_0:   ┤0     ├─■──────┼────────┼──────┼────────┼───────┤0      ├
│      │        │P(π/2)  │P(π)  │        │       │       │
b_1:   ┤1 qft ├────────■────────■──────┼────────┼───────┤1 iqft ├
│      │                        │P(π/2)  │P(π/4) │       │
cout_0: ┤2     ├────────────────────────■────────■───────┤2      ├
└──────┘                                         └───────┘


References:

[1] T. G. Draper, Addition on a Quantum Computer, 2000. arXiv:quant-ph/0008033

[2] Ruiz-Perez et al., Quantum arithmetic with the Quantum Fourier Transform, 2017. arXiv:1411.5949

[3] Vedral et al., Quantum Networks for Elementary Arithmetic Operations, 1995. arXiv:quant-ph/9511018

Parámetros
• num_state_qubits (int) – The number of qubits in either input register for state $$|a\rangle$$ or $$|b\rangle$$. The two input registers must have the same number of qubits.

• kind (str) – The kind of adder, can be 'half' for a half adder or 'fixed' for a fixed-sized adder. A half adder contains a carry-out to represent the most-significant bit, but the fixed-sized adder doesn’t and hence performs addition modulo 2 ** num_state_qubits.

• name (str) – The name of the circuit object.

Muestra

ValueError – If num_state_qubits is lower than 1.

Attributes

ancillas

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

Tipo del valor devuelto

List[AncillaQubit]

calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form

{“gate_name”: {(qubits, params): schedule}}

Tipo del valor devuelto

dict

clbits

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

Tipo del valor devuelto

List[Clbit]

data

Return the circuit data (instructions and context).

Devuelve

a list-like object containing the tuples for the circuit’s data.

Each tuple is in the format (instruction, qargs, cargs), where instruction is an Instruction (or subclass) object, qargs is a list of Qubit objects, and cargs is a list of Clbit objects.

Tipo del valor devuelto

QuantumCircuitData

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

Return the global phase of the circuit in radians.

Tipo del valor devuelto

Union[ParameterExpression, float]

header = 'OPENQASM 2.0;'
instances = 9

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 del valor devuelto

dict

num_ancillas

Return the number of ancilla qubits.

Tipo del valor devuelto

int

num_clbits

Return number of classical bits.

Tipo del valor devuelto

int

num_parameters

Convenience function to get the number of parameter objects in the circuit.

Tipo del valor devuelto

int

num_qubits

Return number of qubits.

Tipo del valor devuelto

int

num_state_qubits

The number of state qubits, i.e. the number of bits in each input register.

Tipo del valor devuelto

int

Devuelve

The number of state qubits.

parameters

Convenience function to get the parameters defined in the parameter table.

Tipo del valor devuelto

ParameterView

prefix = 'circuit'
qubits

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

Tipo del valor devuelto

List[Qubit]