The circuit prepares a superposition state, entangles two qubits, applies a Hadamard gate, and then measures the qubits.
```python
from qiskit import QuantumCircuit
# Create a QuantumCircuit with 2 qubits and 2 classical bits
qc = QuantumCircuit(2, 2)
# Prepare a superposition on qubit 0
qc.h(0)
# Entangle qubit 0 with qubit 1 to mark the path information
qc.cx(0, 1)
# Erase the which-path information by applying Hadamard to qubit 1
qc.h(1)
# Measure both qubits
qc.measure(0, 0)
qc.measure(1, 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"}]}\''