QrBackendV2 module

class QrBackendV2

Supporter class for a qiskit V2 compatible backend object for Quantum Rings SDK meant to be used along with qiskit packages.

Usage:

If the user has already obtained the reference to the QuantumRingsLib.QuantumRingsProvider object, the reference can be provided using the ‘provider’ argument. Otherwise, the user can provide the account’s ‘name’ and ‘token’ as parameters. If the user has saved the account details locally using the QuantumRingsLib.QuantumRingsProvider.save_account api, this method can be called without any arguments.

Example 1:

>>> backend = QrBackendV2()        # Uses the account information that is locally stored.

Example 2:

>>> backend = QrBackendV2(num_qubits = 5)        # Uses the account information that is locally stored, sets the number of qubits to 5.

Example 3:

>>> provider = QuantumRingsLib.QuantumRingsProvider(token = <YOUR_TOKEN>, name = <YOUR_ACCOUNT>)
>>> backend  = QrBackendV2(provider)

Example 4:

>>> backend = QrBackendV2(token = <YOUR_TOKEN>, name = <YOUR_ACCOUNT>)

QrBackendV2(*args, **kwargs) → None

Initialize a BackendV2 based backend for Quantum Rings.

Args:

provider (QuantumRingsLib.QuantumRingsProvider): An optional backwards reference to the QuantumRingsLib.QuantumRingsProvider object.

token (str): An optional access key to the QuantumRingsLib.QuantumRingsProvider.

name (str): An optional account name to be used to autenticate the user.

num_qubits (int): The number of qubits the backend will use.

Raises:

Exception: If not able to obtain the Quantum Rings Provider or the backend.

QrBackendV2.target: Target

Returns the Quantum Rings target associated with the backend.

QrBackendV2.max_circuits: int

Returns the maximum number of circuits the backend can run at a time.

QrBackendV2.num_qubits: int

Returns the number of qubits the backend supports.

_build_target() → None

Builds the Quantum Rings target associated with the backend.

Args:

None

Returns:

None

Raises:

None

_default_options()

Returns the default configuration options.

Args:

None

Returns:

Options

Raises:

None

run(run_input, **run_options)

Executes a qiskit quantum circuit using the Quantum Rings backend

Example:

from qiskit.circuit import QuantumCircuit
from qiskit import QuantumCircuit, transpile, QuantumRegister, ClassicalRegister, AncillaRegister
from qiskit.visualization import plot_histogram
from matplotlib import pyplot as plt

import QuantumRingsLib
from QuantumRingsLib import QuantumRingsProvider
from quantumrings.toolkit.qiskit import QrBackendV2
from quantumrings.toolkit.qiskit import QrJobV1

from matplotlib import pyplot as plt

qr_provider = QuantumRingsProvider(token =<YOUR_TOKEN>, name=<YOUR_ACCOUNT>)

shots = 1000
numberofqubits =  int(qr_provider.active_account()["max_qubits"])
q = QuantumRegister(numberofqubits , 'q')
c = ClassicalRegister(numberofqubits , 'c')
qc = QuantumCircuit(q, c)


# Create the GHZ state (Greenberger-Horne-Zeilinger)
qc.h(0);
for i in range (qc.num_qubits - 1):
    qc.cx(i, i + 1);

# Measure all qubits
qc.measure_all();

# Execute the quantum code
mybackend = QrBackendV2(qr_provider, num_qubits = qc.num_qubits)
qc_transpiled = transpile(qc, mybackend)
job = mybackend.run(qc_transpiled, shots = shots)

result = job.result()
counts = result.get_counts()
plot_histogram(counts)

Args:

run_input (QuantumCircuit):

A qiskit QuantumCircuit object.

shots (int):

The number of times the circuit needs to be executed in repetition. The measurement counts are maintained only for the first 10,000 shots. If more execution cycles are required, a file name can be provided where the measurements are logged.

sync_mode (bool):

default - True - The quantum circuit is executed synchronously.

False - The quantum circuit is executed asynchronously.

performance (str):

One of the following strings that define the quality of the circuit execution.

default - “HighestEfficiency”

“BalancedAccuracy”

“HighestAccuracy”

“Automatic”

quiet (bool):

default - True - Does not print any message

False - Prints some messages, such as which instruction is executed, which may be of help in tracking large circuits

defaults (bool):

default - True - Uses standard internal settings.

False - Uses compact internal settings.

generate_amplitude (bool):

True - Generate amplitudes corresponding to the measurements and print them in the logging file for measurements.

(default) False - Amplitudes are not printed in the logging file.

file (str):

An optional file name for logging the measurements.

Returns:

QrJobV1

Raises:

Exception: If not able to obtain the Quantum Rings Provider or the backend.