Example #1
0
    def test_t1(self):
        """
        Run the simulator with thermal relaxatoin noise.
        Then verify that the calculated T1 matches the t1
        parameter.
        """

        # 25 numbers ranging from 1 to 200, linearly spaced
        num_of_gates = (np.linspace(1, 200, 15)).astype(int)
        gate_time = 0.11
        qubits = [0]

        circs, xdata = t1_circuits(num_of_gates, gate_time, qubits)

        expected_t1 = 10
        error = thermal_relaxation_error(expected_t1, 2*expected_t1, gate_time)
        noise_model = NoiseModel()
        noise_model.add_all_qubit_quantum_error(error, 'id')
        # TODO: Include SPAM errors

        backend = qiskit.Aer.get_backend('qasm_simulator')
        shots = 100
        backend_result = qiskit.execute(
            circs, backend,
            shots=shots,
            backend_options={'max_parallel_experiments': 0},
            noise_model=noise_model).result()

        initial_t1 = expected_t1
        initial_a = 1
        initial_c = 0

        T1Fitter(backend_result, xdata, qubits,
                 fit_p0=[initial_a, initial_t1, initial_c],
                 fit_bounds=([0, 0, -1], [2, expected_t1*1.2, 1]))
Example #2
0
    def test_t1(self):
        """
        Run the simulator with amplitude damping noise.
        Then verify that the calculated T1 matches the amplitude damping
        parameter.
        """

        # 25 numbers ranging from 1 to 200, linearly spaced
        num_of_gates = (np.linspace(1, 200, 25)).astype(int)
        gate_time = 0.11
        num_of_qubits = 2
        qubit = 0

        circs, xdata = t1_circuits(num_of_gates, gate_time, num_of_qubits,
                                   qubit)

        expected_t1 = 10
        gamma = 1 - np.exp(-gate_time / expected_t1)
        error = amplitude_damping_error(gamma)
        noise_model = NoiseModel()
        noise_model.add_all_qubit_quantum_error(error, 'id')
        # TODO: Include SPAM errors

        backend = qiskit.Aer.get_backend('qasm_simulator')
        shots = 300
        backend_result = qiskit.execute(circs,
                                        backend,
                                        shots=shots,
                                        backend_options={
                                            'max_parallel_experiments': 0
                                        },
                                        noise_model=noise_model).result()

        initial_t1 = expected_t1
        initial_a = 1
        initial_c = 0
        fit = T1Fitter(backend_result,
                       shots,
                       xdata,
                       num_of_qubits,
                       qubit,
                       fit_p0=[initial_a, initial_t1, initial_c],
                       fit_bounds=([0, 0, -1], [2, expected_t1 * 1.2, 1]))

        self.assertAlmostEqual(fit.time,
                               expected_t1,
                               delta=20,
                               msg='Calculated T1 is inaccurate')
        self.assertTrue(
            fit.time_err < 30,
            'Confidence in T1 calculation is too low: ' + str(fit.time_err))
Example #3
0
def main():
    # Get backends
    IBMQ.load_account()
    provider = IBMQ.get_provider(hub="ibm-q-ornl", group="anl", project="chm168")
    backend = provider.get_backend("ibmq_burlington")
    plugin_backend = Quac.get_backend("fake_burlington_density_simulator", t1=True, t2=True, meas=False, zz=False)

    # Get calibration circuits
    hardware_properties = FakeBurlington().properties()
    num_gates = np.linspace(10, 500, 30, dtype='int')
    qubits = list(range(len(backend.properties().qubits)))

    t1_circs, t1_delay = t1_circuits(num_gates,
                                     hardware_properties.gate_length('id', [0]) * 1e9,
                                     qubits)

    t2_circs, t2_delay = t2_circuits((num_gates / 2).astype('int'),
                                     hardware_properties.gate_length('id', [0]) * 1e9,
                                     qubits)

    # Formulate real noise model
    real_noise_model = QuacNoiseModel(
        t1_times=[1234, 2431, 2323, 2222, 3454],
        t2_times=[12000, 14000, 14353, 20323, 30232]
    )

    # Formulate initial guess noise model (only same order of magnitude)
    guess_noise_model = QuacNoiseModel(
        t1_times=[1000, 1000, 1000, 1000, 1000],
        t2_times=[10000, 10000, 10000, 10000, 10000]
    )

    # Calculate calibration circuit reference results
    reference_job = execute(t1_circs + t2_circs, plugin_backend,
                            quac_noise_model=real_noise_model,
                            optimization_level=0)
    reference_result = reference_job.result()

    # Calculate optimized noise model
    new_noise_model = optimize_noise_model_ng(
        guess_noise_model=guess_noise_model,
        circuits=t1_circs + t2_circs,
        backend=plugin_backend,
        reference_result=reference_result,
        loss_function=angle_objective_function
    )

    # Show original noise model and optimized noise model
    print(f"Original noise model: {real_noise_model}")
    print(f"New noise model: {new_noise_model}")
Example #4
0
def t1_circuit_execution(
) -> Tuple[qiskit.result.Result, np.array, List[int], float]:
    """
    Create T1 circuits and simulate them.

    Returns:
       *   Backend result.
       *   xdata.
       *   Qubits for the T1 measurement.
       *   T1 that was used in the circuits creation.
    """

    # 15 numbers ranging from 1 to 200, linearly spaced
    num_of_gates = (np.linspace(1, 200, 15)).astype(int)
    gate_time = 0.11
    qubits = [0]

    circs, xdata = t1_circuits(num_of_gates, gate_time, qubits)

    t1_value = 10
    error = thermal_relaxation_error(t1_value, 2 * t1_value, gate_time)
    noise_model = NoiseModel()
    noise_model.add_all_qubit_quantum_error(error, 'id')
    # TODO: Include SPAM errors

    backend = qiskit.Aer.get_backend('qasm_simulator')
    shots = 100
    backend_result = qiskit.execute(circs,
                                    backend,
                                    shots=shots,
                                    seed_simulator=SEED,
                                    backend_options={
                                        'max_parallel_experiments': 0
                                    },
                                    noise_model=noise_model,
                                    optimization_level=0).result()

    return backend_result, xdata, qubits, t1_value
Example #5
0
from qiskit.ignis.characterization.coherence import T1Fitter, T2StarFitter, T2Fitter
from qiskit.ignis.characterization.coherence import t1_circuits, t2_circuits, t2star_circuits

from qiskit import IBMQ, compile

# Measure the value of T1 (relaxation) time
# 12 numbers ranging from 10 to 1000, logarithmically spaced
# extra point at 1500
num_of_gates = np.append((np.logspace(1, 3, 12)).astype(int), np.array([1500]))
gate_time = 0.1  # time of running a single gate

# Select the qubits whose T1 are to be measured
qubits = [0]

# Generate experiments
circs, xdata = t1_circuits(num_of_gates, gate_time, qubits)

# Run the simulator
# IBMQ.backends()
#[
# <IBMQBackend('ibmqx4') from IBMQ()>,
# <IBMQBackend('ibmqx2') from IBMQ()>,
# <IBMQBackend('ibmq_16_melbourne') from IBMQ()>,
# <IBMQBackend('ibmq_qasm_simulator') from IBMQ()>
# ]
# IBMQ device information:
# https://www.research.ibm.com/ibm-q/technology/devices/#ibmqx4

backend = qiskit.Aer.get_backend('qasm_simulator')
shots = 1024
backend_result = qiskit.execute(circs, backend, shots=shots).result()