def test_vqe_auto_symmetry_freeze_core(self): """ Auto symmetry reduction, with freeze core using VQE """ core = Hamiltonian(transformation=TransformationType.FULL, qubit_mapping=QubitMappingType.JORDAN_WIGNER, two_qubit_reduction=False, freeze_core=True, orbital_reduction=None, z2symmetry_reduction='auto') qubit_op, aux_ops = core.run(self.qmolecule) self.assertEqual(qubit_op.num_qubits, 6) num_orbitals = core.molecule_info[core.INFO_NUM_ORBITALS] num_particles = core.molecule_info[core.INFO_NUM_PARTICLES] qubit_mapping = 'jordan_wigner' two_qubit_reduction = core.molecule_info[core.INFO_TWO_QUBIT_REDUCTION] z2_symmetries = core.molecule_info[core.INFO_Z2SYMMETRIES] initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(qubit_op, var_form=var_form, optimizer=SLSQP(maxiter=500), aux_operators=aux_ops) vqe.quantum_instance = BasicAer.get_backend('statevector_simulator') result = core.process_algorithm_result(vqe.compute_minimum_eigenvalue()) self._validate_result(result) self.assertEqual(core.molecule_info[core.INFO_Z2SYMMETRIES].tapering_values, [-1, 1, 1, -1])
def _compute_gradients(self, excitation_pool, theta, delta, var_form, operator, optimizer): """ Computes the gradients for all available excitation operators. Args: excitation_pool (list): pool of excitation operators theta (list): list of (up to now) optimal parameters delta (float): finite difference step size (for gradient computation) var_form (VariationalForm): current variational form operator (LegacyBaseOperator): system Hamiltonian optimizer (Optimizer): classical optimizer algorithm Returns: list: List of pairs consisting of gradient and excitation operator. """ res = [] # compute gradients for all excitation in operator pool for exc in excitation_pool: # push next excitation to variational form var_form.push_hopping_operator(exc) # construct auxiliary VQE instance vqe = VQE(operator, var_form, optimizer) vqe.quantum_instance = self.quantum_instance # evaluate energies parameter_sets = theta + [-delta] + theta + [delta] energy_results = vqe._energy_evaluation(np.asarray(parameter_sets)) # compute gradient gradient = (energy_results[0] - energy_results[1]) / (2 * delta) res.append((np.abs(gradient), exc)) # pop excitation from variational form var_form.pop_hopping_operator() return res
def test_reuse(self): """Test re-using a VQE algorithm instance.""" vqe = VQE() with self.subTest(msg='assert running empty raises AquaError'): with self.assertRaises(AquaError): _ = vqe.run() var_form = TwoLocal(rotation_blocks=['ry', 'rz'], entanglement_blocks='cz') vqe.var_form = var_form with self.subTest(msg='assert missing operator raises AquaError'): with self.assertRaises(AquaError): _ = vqe.run() vqe.operator = self.h2_op with self.subTest(msg='assert missing backend raises AquaError'): with self.assertRaises(AquaError): _ = vqe.run() vqe.quantum_instance = self.statevector_simulator with self.subTest(msg='assert VQE works once all info is available'): result = vqe.run() self.assertAlmostEqual(result.eigenvalue.real, self.h2_energy, places=5) operator = PrimitiveOp( np.array([[1, 0, 0, 0], [0, -1, 0, 0], [0, 0, 2, 0], [0, 0, 0, 3]])) with self.subTest(msg='assert minimum eigensolver interface works'): result = vqe.compute_minimum_eigenvalue(operator) self.assertAlmostEqual(result.eigenvalue.real, -1.0, places=5)
def test_vqe_reuse(self): """ Test vqe reuse """ vqe = VQE() with self.assertRaises(AquaError): _ = vqe.run() var_form = TwoLocal(rotation_blocks=['ry', 'rz'], entanglement_blocks='cz') vqe.var_form = var_form with self.assertRaises(AquaError): _ = vqe.run() vqe.operator = self.qubit_op with self.assertRaises(AquaError): _ = vqe.run() qinst = QuantumInstance(BasicAer.get_backend('statevector_simulator')) vqe.quantum_instance = qinst result = vqe.run() self.assertAlmostEqual(result.eigenvalue.real, -1.85727503, places=5) operator = PrimitiveOp( np.array([[1, 0, 0, 0], [0, -1, 0, 0], [0, 0, 2, 0], [0, 0, 0, 3]])) vqe.operator = operator result = vqe.run() self.assertAlmostEqual(result.eigenvalue.real, -1.0, places=5)
def test_vqe_reuse(self): """ Test vqe reuse """ vqe = VQE() with self.assertRaises(AquaError): _ = vqe.run() num_qubits = self.qubit_op.num_qubits var_form = RY(num_qubits, depth=3) vqe.var_form = var_form with self.assertRaises(AquaError): _ = vqe.run() vqe.operator = self.qubit_op with self.assertRaises(AquaError): _ = vqe.run() qinst = QuantumInstance(BasicAer.get_backend('statevector_simulator')) vqe.quantum_instance = qinst result = vqe.run() self.assertAlmostEqual(result.eigenvalue.real, -1.85727503, places=5) operator = MatrixOperator(np.array([[1, 0, 0, 0], [0, -1, 0, 0], [0, 0, 2, 0], [0, 0, 0, 3]])) vqe.operator = operator result = vqe.run() self.assertAlmostEqual(result.eigenvalue.real, -1.0, places=5)
def vqe_create_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries, initial_point = system.opt_amplitudes, noise = noise): initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) if noise: var_form = EfficientSU2(num_qubits = no_qubits, entanglement="linear") else: var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(var_form=var_form, optimizer=SLSQP(maxiter=500), include_custom=True, initial_point = initial_point) vqe.quantum_instance = backend return vqe
def cb_create_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries): initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(var_form=var_form, optimizer=SLSQP(maxiter=500)) vqe.quantum_instance = BasicAer.get_backend('statevector_simulator') return vqe
def cb_default_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries): """ Default solver """ initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(var_form=var_form) vqe.quantum_instance = quantum_instance return vqe
def vqe_create_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries): initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(var_form=var_form, optimizer=SLSQP(maxiter=500), include_custom=True) vqe.quantum_instance = backend return vqe
def vqe_create_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries): initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) # var_form = UCCSD(num_orbitals=num_orbitals, # num_particles=num_particles, # initial_state=initial_state, # qubit_mapping=qubit_mapping, # two_qubit_reduction=two_qubit_reduction, # z2_symmetries=z2_symmetries) var_form = EfficientSU2(num_qubits=no_qubits, entanglement="linear") vqe = VQE(var_form=var_form, optimizer=SPSA(maxiter=500), include_custom=True) vqe.quantum_instance = quantum_instance return vqe
def cb_create_solver(num_particles, num_orbitals, qubit_mapping, two_qubit_reduction, z2_symmetries): initial_state = HartreeFock(num_orbitals, num_particles, qubit_mapping, two_qubit_reduction, z2_symmetries.sq_list) var_form = UCCSD(num_orbitals=num_orbitals, num_particles=num_particles, initial_state=initial_state, qubit_mapping=qubit_mapping, two_qubit_reduction=two_qubit_reduction, z2_symmetries=z2_symmetries) vqe = VQE(var_form=var_form, include_custom=True, optimizer=SLSQP(maxiter=5000), max_evals_grouped=256) vqe.quantum_instance = Aer.get_backend('qasm_simulator') vqe.quantum_instance.backend_options['backend_options'] = { 'max_parallel_experiments': threads, 'method': method } return vqe