def test_expectation(self, backend):
qstate = statevector.computational_zeros(6, backend=backend)
qstate.apply_circuit([
Gate('X', [], [0]),
Gate('CX', [], [0, 3]),
Gate('H', [], [2]),
])
observable = 1.5 * Observable.sum([
Observable.Z(0) * 2,
Observable.Z(1),
Observable.Z(2) * 2,
Observable.Z(3),
])
self.assertTrue(np.isclose(qstate.expectation(observable), -3))
def test_expectation_single_layer(self, backend):
qstate = peps.computational_zeros(2, 3, backend=backend)
qstate.apply_circuit([
Gate('X', [], [0]),
Gate('CX', [], [0,3]),
Gate('H', [], [2]),
])
observable = 1.5 * Observable.sum([
Observable.Z(0) * 2,
Observable.Z(1),
Observable.Z(2) * 2,
Observable.Z(3),
])
contract_option = peps.SingleLayer(ImplicitRandomizedSVD(rank=2))
self.assertTrue(backend.isclose(qstate.expectation(observable, contract_option=contract_option), -3))
def test_expectation_use_cache_approx(self, backend):
qstate = peps.computational_zeros(2, 3, backend=backend)
qstate.apply_circuit([
Gate('X', [], [0]),
Gate('CX', [], [0,3]),
Gate('H', [], [2]),
], update_option=peps.DirectUpdate(ImplicitRandomizedSVD(rank=2)))
observable = 1.5 * Observable.sum([
Observable.Z(0) * 2,
Observable.Z(1),
Observable.Z(2) * 2,
Observable.Z(3),
])
contract_option = peps.BMPS(ReducedSVD(rank=2))
self.assertTrue(backend.isclose(qstate.expectation(observable, use_cache=True, contract_option=contract_option), -3))
def test_expectation_use_cache(self, backend):
qstate = peps.computational_zeros(2, 3, backend=backend)
qstate.apply_circuit([
Gate('X', [], [0]),
Gate('CX', [], [0, 3]),
Gate('H', [], [2]),
])
observable = 1.5 * Observable.sum([
Observable.Z(0) * 2,
Observable.Z(1),
Observable.Z(2) * 2,
Observable.Z(3),
])
self.assertTrue(
backend.isclose(qstate.expectation(observable, use_cache=True),
-3))