# For the same operator, when I use qiskit's VQE and QAOA solutions, the results are completely different

Specifically, I can't get the correct result using QAOA，A total of 6 qubits were used in this work，this is part of my code using VQE and QAOA localsim = BasicAer.get_backend('qasm_simulator')

optimizer = SPSA(max_trials=500)
ansatz = TwoLocal(rotation_blocks='ry', entanglement_blocks='cz')
vqe = VQE(op, ansatz, optimizer = optimizer)
results1 = vqe.run(localsim)


and

from qiskit import QuantumCircuit
optimizer = COBYLA(maxiter = 100)
depth = 10
initial = QuantumCircuit(nbr_qubits)
qaoa = QAOA(operator=op, optimizer=optimizer, p = depth,initial_state = initial, quantum_instance=localsim)
results2 = qaoa.run()


I tried changing depth and optimizer type but it didn't work，The following two pictures are the results of VQE and QAOA respectively

Is it because I'm using QAOA incorrectly?

• What was your operator? May 29 at 18:56
• op is an ising hamiltonian May 30 at 4:39