def test_qft(self):
trial_state = Computer(4)
trial_circ = build_circuit('X_0 X_1')
trial_state.apply_circuit(trial_circ)
# verify direct transformation
qft(trial_state, 0, 3)
a1_dag_a2 = build_operator('1.0, Z_0')
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(0, abs=1.0e-16)
# test unitarity
qft(trial_state, 0, 2)
rev_qft(trial_state, 0, 2)
a1_dag_a2 = build_operator('1.0, Z_0')
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(0, abs=1.0e-16)
# test reverse transformation
qft(trial_state, 0, 3)
a1_dag_a2 = build_operator('1.0, Z_0')
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(1.0, abs=1.0e-14)
def test_advanced_gates(self):
print('\n')
trial_state = Computer(4)
trial_circ = build_circuit('X_0 X_1')
trial_state.apply_circuit(trial_circ)
# verify Toffoli gate
T_circ = Toffoli(0, 1, 2)
print(T_circ.str())
trial_state.apply_circuit(T_circ) # This should turn the state to 1110
a1_dag_a2 = build_operator('1.0, Z_2')
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(-1, abs=9e-16) # Measure qubit 2 should give -1
# verify Fredkin gate
F_circ = Fredkin(1, 2, 3)
print(F_circ.str())
trial_state.apply_circuit(F_circ) # This should turn the state to 1101
# trial_state.apply_circuit_safe(F_circ) # This should turn the state to 1101
a1_dag_a2 = build_operator('1.0, Z_2')
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(1, abs=9e-16) # Measure qubit 2 should give +1
def test_op_exp_val_1(self):
# test direct expectation value measurement
trial_state = Computer(4)
trial_prep = [None] * 5
trial_prep[0] = gate('H', 0, 0)
trial_prep[1] = gate('H', 1, 1)
trial_prep[2] = gate('H', 2, 2)
trial_prep[3] = gate('H', 3, 3)
trial_prep[4] = gate('cX', 0, 1)
trial_circ = Circuit()
#prepare the circuit
for gate_ in trial_prep:
trial_circ.add(gate_)
# use circuit to prepare trial state
trial_state.apply_circuit(trial_circ)
# gates needed for [a1^ a2] operator
X1 = gate('X', 1, 1)
X2 = gate('X', 2, 2)
Y1 = gate('Y', 1, 1)
Y2 = gate('Y', 2, 2)
# initialize circuits to make operator
circ1 = Circuit()
circ1.add(X2)
circ1.add(Y1)
circ2 = Circuit()
circ2.add(Y2)
circ2.add(Y1)
circ3 = Circuit()
circ3.add(X2)
circ3.add(X1)
circ4 = Circuit()
circ4.add(Y2)
circ4.add(X1)
#build the quantum operator for [a1^ a2]
a1_dag_a2 = QubitOperator()
a1_dag_a2.add(0.0 - 0.25j, circ1)
a1_dag_a2.add(0.25, circ2)
a1_dag_a2.add(0.25, circ3)
a1_dag_a2.add(0.0 + 0.25j, circ4)
#get direct expectatoin value
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(0.25, abs=2.0e-16)
def test_io_simplified(self):
# test direct expectation value measurement
trial_state = Computer(4)
trial_circ = build_circuit('H_0 H_1 H_2 H_3 cX_0_1')
# use circuit to prepare trial state
trial_state.apply_circuit(trial_circ)
#build the quantum operator for [a1^ a2]
a1_dag_a2 = build_operator('0.0-0.25j, X_2 Y_1; 0.25, Y_2 Y_1; \
0.25, X_2 X_1; 0.0+0.25j, Y_2 X_1')
#get direct expectatoin value
exp = trial_state.direct_op_exp_val(a1_dag_a2)
assert exp == approx(0.25, abs=2.0e-16)