This quantum circuit creates a superposition, applies a phase shift, recombines the paths, and measures the result.
```python
from qiskit import *
# Create circuit with 1 qubit and 1 classical bit
qc = QuantumCircuit(1, 1)
# Create superposition (first beam splitter)
qc.h(0)
# Apply a phase shift to simulate path difference
qc.rz(1.5708, 0) # Phase shift of pi/2 radians
# Recombine paths (second beam splitter)
qc.h(0)
# Measure the result
qc.measure(0, 0)
```
'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"}]}\''