This quantum circuit prepares a superposition representing three paths, applies phase shifts, recombines the paths, and measures the qubits.
```python
from qiskit import QuantumCircuit
import numpy as np
# Create a quantum circuit with 2 qubits and 2 classical bits
qc = QuantumCircuit(2, 2)
# Prepare a superposition representing three paths
theta = 2 * np.arccos(1 / np.sqrt(3))
qc.ry(theta, 0)
qc.cx(0, 1)
qc.h(0)
# Apply phase shifts to different paths
qc.p(np.pi / 2, 0)
qc.p(np.pi, 1)
# Recombine the paths
qc.h(0)
qc.cx(0, 1)
qc.ry(-theta, 0)
# Measure the qubits
qc.measure([0, 1], [0, 1])
```'Failed to run program: \'409 Client Error: Conflict for url: https://api.quantum.ibm.com/runtime/jobs. {"errors":[{"message":"You have reached the limit of 3 pending jobs. Please wait for a job to complete or cancel one before submitting anything new.","code":3458,"solution":"Wait until some previous jobs were finished. You can cancel pending jobs to run new jobs.","more_info":"https://docs.quantum-computing.ibm.com/errors"}]}\''