backend_device = ibmqprovider.get_backend('ibmqx4')
# 0. build circuit
from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit
q = QuantumRegister(2)
c = ClassicalRegister(2)
circ = QuantumCircuit(q, c)
circ.cx(q[0], q[1])
circ.cx(q[0], q[1])
circ.cx(q[0], q[1])
circ.cx(q[0], q[1])
circ.measure(q, c)
# draw circuit
from qiskit.tools.visualization import plot_circuit
plot_circuit(circ)
# 1. standard compile -- standard qiskit passes, when no PassManager given
from qiskit import transpiler, load_qasm_string
qobj_standard = transpiler.compile(circ, backend_device)
compiled_standard = load_qasm_string(
qobj_standard['circuits'][0]['compiled_circuit_qasm'])
plot_circuit(compiled_standard)
# 2. custom compile -- customize PassManager to run specific circuit transformations
from qiskit.transpiler.passes import CXCancellation
pm = transpiler.PassManager()
pm.add_pass(CXCancellation())
qobj_custom = transpiler.compile(circ, backend_device, pass_manager=pm)
compiled_custom = load_qasm_string(
qobj_custom['circuits'][0]['compiled_circuit_qasm'])
0, 0, 0, 0, 1 / math.sqrt(8) * complex(1, 0),
1 / math.sqrt(8) * complex(0, 1), 0, 0, 0, 0,
1 / math.sqrt(4) * complex(1, 0), 1 / math.sqrt(8) * complex(1, 0)
]
circuit.initialize(desired_vector, [qr[0], qr[1], qr[2], qr[3]])
circuit.measure(qr[0], cr[0])
circuit.measure(qr[1], cr[1])
circuit.measure(qr[2], cr[2])
circuit.measure(qr[3], cr[3])
QASM_source = circuit.qasm()
print(QASM_source)
plot_circuit(circuit)
###############################################################
# Execute on a simulator backend.
###############################################################
shots = 1024
# Desired vector
print("Desired probabilities...")
print(str(list(map(lambda x: format(abs(x * x), '.3f'), desired_vector))))
# Initialize on local simulator
result = execute(circuit, backend='local_qasm_simulator', shots=shots).result()
print("Probabilities from simulator...[%s]" % result)
n_qubits_qureg = qr.size
from qiskit import QuantumProgram
from qiskit.tools.visualization import plot_histogram, circuit_drawer, plot_circuit
qp = QuantumProgram()
nq = 2 # number of qubits
q = qp.create_quantum_register("q", nq)
c = qp.create_classical_register("c", nq)
circuits = ['testQ']
testQ = qp.create_circuit(circuits[0], [q], [c])
testQ.h(q[0])
testQ.cx(q[0], q[1])
testQ.measure(q[0], c[0])
testQ.measure(q[1], c[1])
results = qp.execute(circuits,
backend='local_qasm_simulator',
shots=1024,
seed=1)
plot_histogram(results.get_counts(circuits[0]))
#circuit_drawer(testQ)
plot_circuit(testQ)
backend = lowest_pending_jobs()
print("The best backend is " + backend)
q = QuantumRegister(2)
c = ClassicalRegister(2)
qc = QuantumCircuit(q, c)
qc.h(q[0])
qc.cx(q[0], q[1])
qc.measure(q, c)
job_exp = execute(qc, backend=backend, shots=1024, max_credits=3)
lapse = 0
interval = 10
while not job_exp.done:
print('Status @ {} seconds'.format(interval * lapse))
print(job_exp.status)
time.sleep(interval)
lapse += 1
print(job_exp.status)
plot_histogram(job_exp.result().get_counts(qc))
print('You have made entanglement!')
# Keita Memo
# I don't know why but circuit_drawer does not work correctly.
# So I use plot_circuit instead.
# circuit_drawer(qc)
plot_circuit(qc)
0,
0,
1 / math.sqrt(4) * complex(1, 0),
1 / math.sqrt(8) * complex(1, 0)]
circuit.initialize(desired_vector, [qr[0], qr[1], qr[2], qr[3]])
circuit.measure(qr[0], cr[0])
circuit.measure(qr[1], cr[1])
circuit.measure(qr[2], cr[2])
circuit.measure(qr[3], cr[3])
QASM_source = Q_program.get_qasm("initializer_circ")
print(QASM_source)
plot_circuit(circuit)
###############################################################
# Set the backend name and coupling map.
###############################################################
device = 'ibmqx2'
coupling_map = {0: [1, 2],
1: [2],
2: [],
3: [2, 4],
4: [2]}
circuits = ['initializer_circ']
shots = 1024
###############################################################
# Set up the API and execute the program.