modules.applications.qml.qleet.interface.circuit.CircuitDescriptor

class CircuitDescriptor(circuit: QuantumCircuit, params: List[Symbol | Parameter], cost_function: PauliList | None = None)

Bases: object

The interface for users to provide a circuit in any framework and visualize it in qLEET.

It consists of 3 parts: * Circuit: which has the full ansatz preparation from the start where * Params: list of parameters which are used to parameterize the circuit * Cost Function: presently a pauli string, which we measure to get the

output we are optimizing over

Combined they form the full the parameterized quantum circuit from the initial qubits to the end measurement.

__init__(circuit: QuantumCircuit, params: List[Symbol | Parameter], cost_function: PauliList | None = None)

Constructor for the CircuitDescriptor

Parameters:

• circuit (Circuit in any supported library) -- The full circuit which generates the required quantum state

• params (list[sympy.Symbol]) -- The list of parameters to optimize over

• cost_function (PauliSum in any supported library) -- The measurement operation as a PauliString

If you are not providing the full list of parameters of the circuit because you don't want to optimize over some of those parameters, because use a Parameter Resolver to resolve those parameter values before you pass in the lists. The list of parameters passed in here ought to be complete.

Methods

__init__(circuit, params[, cost_function])	Constructor for the CircuitDescriptor
from_qasm(qasm_str, params, cost_function[, ...])	Generate the descriptor from OpenQASM string

Attributes

default_backend	Returns the backend in which the user had provided the circuit.
num_qubits	Get the number of qubits for a circuit :return: the number of qubits in the circuit :rtype: int :raises ValueError: if unsupported circuit framework is given
parameters	The list of sympy symbols to resolve as parameters, will be swept from 0 to 2*pi :return: list of parameters
qiskit_circuit	Get the circuit in qiskit :return: the qiskit representation of the circuit :rtype: qiskit.QuantumCircuit

property default_backend: str

Returns the backend in which the user had provided the circuit. :returns: The name of the default backend :rtype: str :raises ValueError: if the given circuit is not from a supported library

classmethod from_qasm(qasm_str: str, params: List[Symbol | Parameter], cost_function: PauliList | None, backend: str = 'qiskit')

Generate the descriptor from OpenQASM string

Parameters:

• qasm_str (str) -- OpenQASM string for each part of the circuit

• params (list[sympy.Symbol]) -- list of sympy symbols which act as parameters for the PQC

• cost_function (PauliSum) -- pauli-string operator to implement cost function

• backend (str) -- backend for the circuit descriptor objects

Returns:

The CircuitDescriptor object

Return type:

CircuitDescriptor

Raises:

ValueError -- if one of the 3 supported backends is not the input

property num_qubits: int

Get the number of qubits for a circuit :return: the number of qubits in the circuit :rtype: int :raises ValueError: if unsupported circuit framework is given

property parameters: List[Symbol | Parameter]

The list of sympy symbols to resolve as parameters, will be swept from 0 to 2*pi :return: list of parameters

property qiskit_circuit: QuantumCircuit

Get the circuit in qiskit :return: the qiskit representation of the circuit :rtype: qiskit.QuantumCircuit