def test_homodyne_measurement_vacuum(self, setup_eng, tol):
"""MeasureX and MeasureP leave the mode in the vacuum state"""
eng, prog = setup_eng(2)
with prog.context as q:
ops.Coherent(a, c) | q[0]
ops.Coherent(b, c) | q[1]
ops.MeasureX | q[0]
ops.MeasureP | q[1]
eng.run(prog)
assert np.all(eng.backend.is_vacuum(tol))
def test_heterodyne(self, setup_eng, tol):
"""Test Fock measurements return expected results"""
eng, prog = setup_eng(2)
a = [0.43 - 0.12j, 0.02 + 0.2j]
with prog.context as q:
ops.Coherent(a[0]) | q[0]
ops.Coherent(a[1]) | q[1]
ops.MeasureHD | q[0]
ops.MeasureHD | q[1]
eng.run(prog)
# Heterodyne measurements put the modes into vacuum state
assert eng.backend.is_vacuum(tol)
def test_heterodyne(self, setup_eng, tol):
"""Test heterodyne measurements return expected results"""
eng, prog = setup_eng(2)
a0 = 0.44643
phi0 = -0.2721457
a1 = 0.200998
phi1 = 1.47112755
with prog.context as q:
ops.Coherent(a0, phi0) | q[0]
ops.Coherent(a1, phi1) | q[1]
ops.MeasureHD | q[0]
ops.MeasureHD | q[1]
eng.run(prog)
# Heterodyne measurements put the modes into vacuum state
assert eng.backend.is_vacuum(tol)
def test_homodyne_measurement_vacuum_phi(self, setup_eng, tol):
"""Homodyne measurements leave the mode in the vacuum state"""
eng, prog = setup_eng(2)
with prog.context as q:
ops.Coherent(a, b) | q[0]
ops.MeasureHomodyne(c) | q[0]
eng.run(prog)
assert np.all(eng.backend.is_vacuum(tol))
def test_coherent_state_has_photons(self, setup_eng, hbar):
"""Test that a coherent state with a mean photon number of 4 and sampled 100 times will produce photons"""
shots = 100
eng, prog = setup_eng(1)
alpha = 2
with prog.context as q:
ops.Coherent(alpha) | q[0]
ops.MeasureFock() | q[0]
state = eng.run(prog).state
samples = np.array(eng.run(prog, shots=shots)).flatten()
assert not np.all(samples == np.zeros_like(samples, dtype=int))
