This circuit simulates the time evolution of a two-qubit system under a Hamiltonian H = X⊗X + Y⊗Y + Z⊗Z.
```python
from qiskit import QuantumCircuit
import numpy as np
# Create a circuit with 2 qubits and 2 classical bits
qc = QuantumCircuit(2, 2)
# Initialize qubits in superposition
qc.h(0)
qc.h(1)
# Time parameter for Hamiltonian evolution
t = np.pi / 4 # You can adjust this value
# Simulate time evolution under a custom Hamiltonian H = X⊗X + Y⊗Y + Z⊗Z
# Using Trotter-Suzuki decomposition for e^{-iHt}
# XX interaction
qc.h([0, 1])
qc.cx(0, 1)
qc.rz(2 * t, 1)
qc.cx(0, 1)
qc.h([0, 1])
# YY interaction
qc.rx(np.pi / 2, [0, 1])
qc.cx(0, 1)
qc.rz(2 * t, 1)
qc.cx(0, 1)
qc.rx(-np.pi / 2, [0, 1])
# ZZ interaction
qc.cx(0, 1)
qc.rz(2 * t, 1)
qc.cx(0, 1)
# 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"}]}\''