def test_squeezing(self):
"""Test squeezing gives correct means and cov"""
self.eng.reset()
q = self.eng.register
x = 0.2
p = 0.3
r = 0.42
phi = 0.123
H, t = squeezing(r, phi, hbar=self.hbar)
with self.eng:
Xgate(x) | q[0]
Zgate(p) | q[0]
GaussianPropagation(H, t) | q[0]
state = self.eng.run('gaussian')
# test the covariance matrix
res = state.cov()
S = rot(phi / 2) @ np.diag(np.exp([-r, r])) @ rot(phi / 2).T
V = S @ S.T * self.hbar / 2
self.assertTrue(np.allclose(res, V))
# test the vector of means
res = state.means()
exp = S @ np.array([x, p])
self.assertTrue(np.allclose(res, exp))
def test_rotation(self):
"""Test rotation gives correct means and cov"""
self.eng.reset()
q = self.eng.register
x = 0.2
p = 0.3
phi = 0.123
H, t = rotation(phi, hbar=self.hbar)
with self.eng:
Xgate(x) | q[0]
Zgate(p) | q[0]
Sgate(2) | q[0]
GaussianPropagation(H, t) | q[0]
state = self.eng.run('gaussian')
# test the covariance matrix
res = state.cov()
V = np.diag([np.exp(-4), np.exp(4)]) * self.hbar / 2
expected = rot(phi) @ V @ rot(phi).T
self.assertTrue(np.allclose(res, expected))
# test the vector of means
res = state.means()
exp = rot(phi) @ np.diag(np.exp([-2, 2])) @ np.array([x, p])
self.assertTrue(np.allclose(res, exp))
def test_rotation(self, hbar):
"""Test rotation gives correct means and cov"""
prog = sf.Program(1)
eng = sf.Engine("gaussian")
x = 0.2
p = 0.3
phi = 0.123
H, t = rotation(phi, hbar=hbar)
with prog.context as q:
Xgate(x) | q[0]
Zgate(p) | q[0]
Sgate(2) | q[0]
GaussianPropagation(H, t) | q[0]
state = eng.run(prog).state
# test the covariance matrix
res = state.cov()
V = np.diag([np.exp(-4), np.exp(4)]) * hbar / 2
expected = rot(phi) @ V @ rot(phi).T
assert np.allclose(res, expected)
# test the vector of means
res = state.means()
exp = rot(phi) @ np.diag(np.exp([-2, 2])) @ np.array([x, p])
assert np.allclose(res, exp)
def test_squeezing(self, hbar):
"""Test squeezing gives correct means and cov"""
prog = sf.Program(1)
eng = sf.Engine("gaussian")
x = 0.2
p = 0.3
r = 0.42
phi = 0.123
H, t = squeezing(r, phi, hbar=hbar)
with prog.context as q:
Xgate(x) | q[0]
Zgate(p) | q[0]
GaussianPropagation(H, t) | q[0]
state = eng.run(prog).state
# test the covariance matrix
res = state.cov()
S = rot(phi / 2) @ np.diag(np.exp([-r, r])) @ rot(phi / 2).T
V = S @ S.T * hbar / 2
assert np.allclose(res, V)
# test the vector of means
res = state.means()
exp = S @ np.array([x, p])
assert np.allclose(res, exp)
def test_rotated_squeezed(self, setup_eng, hbar, tol):
"""Testing a rotated squeezed state"""
eng, prog = setup_eng(3)
r = 0.1
phi = 0.2312
v1 = (hbar / 2) * np.diag([np.exp(-r), np.exp(r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with prog.context as q:
ops.Gaussian(cov, decomp=False) | q
state = eng.run(prog).state
assert np.allclose(state.cov(), cov, atol=tol)
def test_covariance_rotated_squeezed(self):
self.logTestName()
q = self.eng.register
r = 0.1
phi = 0.2312
v1 = (self.hbar / 2) * np.diag([np.exp(-r), np.exp(r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with self.eng:
Gaussian(cov, decomp=False) | q
state = self.eng.run()
self.assertAllAlmostEqual(state.cov(), cov, delta=self.tol)
def test_rotated_squeezed(self, setup_eng, hbar, tol):
"""Testing decomposed rotated squeezed state"""
eng, q = setup_eng(3)
r = 0.1
phi = 0.2312
v1 = (hbar / 2) * np.diag([np.exp(-r), np.exp(r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with eng:
ops.Gaussian(cov) | q
state = eng.run()
assert np.allclose(state.cov(), cov, atol=tol)
assert np.all(len(eng.cmd_applied[0]) == 3)
def test_covariance_rotated_squeezed(self):
self.eng.reset()
q = self.eng.register
r = 0.1
phi = 0.2312
v1 = (self.hbar / 2) * np.diag([np.exp(-r), np.exp(r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with self.eng:
CovarianceState(cov) | q
state = self.eng.run(backend=self.backend_name, cutoff_dim=self.D)
self.assertAllAlmostEqual(state.cov(), cov, delta=self.tol)
self.assertAllEqual(len(self.eng.cmd_applied), 3)
def test_rotated_squeezed(self, setup_eng, cutoff, hbar, tol):
eng, q = setup_eng(3)
r = 0.1
phi = 0.2312
in_state = squeezed_state(r, phi, basis="fock", fock_dim=cutoff)
v1 = (hbar / 2) * np.diag([np.exp(-2 * r), np.exp(2 * r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with eng:
ops.Gaussian(cov) | q
state = eng.run()
assert len(eng.cmd_applied[0]) == 3
for n in range(3):
assert np.allclose(state.fidelity(in_state, n), 1, atol=tol)
def test_covariance_rotated_squeezed(self):
self.logTestName()
q = self.eng.register
r = 0.1
phi = 0.2312
in_state = squeezed_state(r, phi, basis='fock', fock_dim=self.D)
v1 = (self.hbar / 2) * np.diag([np.exp(-2 * r), np.exp(2 * r)])
A = changebasis(3)
cov = A.T @ block_diag(*[rot(phi) @ v1 @ rot(phi).T] * 3) @ A
with self.eng:
Gaussian(cov) | q
state = self.eng.run(**self.kwargs)
self.assertAllEqual(len(self.eng.cmd_applied[0]), 3)
for n in range(3):
self.assertAllAlmostEqual(state.fidelity(in_state, n),
1,
delta=self.tol)