This quantum circuit initializes all eight qubits to the superposition state and applies controlled-Z gates to form a cube-shaped cluster state.
```python
from qiskit import *
# Create circuit with 8 qubits and 8 classical bits
qc = QuantumCircuit(8, 8)
# Initialize all qubits to the |+⟩ state
qc.h(range(8))
# Apply controlled-Z gates to form a cube-shaped cluster state
# Edges of a cube connecting the qubits
cube_edges = [
(0, 1), (1, 2), (2, 3), (3, 0), # Bottom face edges
(4, 5), (5, 6), (6, 7), (7, 4), # Top face edges
(0, 4), (1, 5), (2, 6), (3, 7) # Side edges connecting top and bottom faces
]
# Apply controlled-Z gates between qubits connected by edges
for edge in cube_edges:
qc.cz(edge[0], edge[1])
# Measure all qubits
qc.measure(range(8), range(8))
```'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"}]}\''