def get_noisy_dynamics(self, dims):
"""
Return a list of Pulse object with only trivial ideal pulse (H=0) but
non-trivial lindblad noise.
Parameters
----------
dims: list, optional
The dimension of the components system, the default value is
[2,2...,2] for qubits system.
Returns
-------
lindblad_noise: list of :class:`qutip.qip.Pulse`
A list of Pulse object with only trivial ideal pulse (H=0) but
non-trivial lindblad noise.
"""
if isinstance(dims, list):
N = len(dims)
else:
N = dims
# time-independent
if (self.coeff is None) and (self.tlist is None):
self.coeff = True
lindblad_noise = Pulse(None, None)
for c_op in self.c_ops:
if self.all_qubits:
for targets in range(N):
lindblad_noise.add_lindblad_noise(c_op, targets,
self.tlist, self.coeff)
else:
lindblad_noise.add_lindblad_noise(c_op, self.targets,
self.tlist, self.coeff)
return lindblad_noise
def TestPulseConstructor():
"""
Test for creating empty Pulse, Pulse with constant coefficients etc.
"""
coeff = np.array([0.1, 0.2, 0.3, 0.4])
tlist = np.array([0., 1., 2., 3.])
ham = sigmaz()
# Special ways of initializing pulse
pulse2 = Pulse(sigmax(), 0, tlist, True)
assert_allclose(pulse2.get_ideal_qobjevo(2).ops[0].qobj,
tensor(sigmax(), identity(2)))
pulse3 = Pulse(sigmay(), 0)
assert_allclose(pulse3.get_ideal_qobjevo(2).cte.norm(), 0.)
pulse4 = Pulse(None, None) # Dummy empty ham
assert_allclose(pulse4.get_ideal_qobjevo(2).cte.norm(), 0.)
tlist_noise = np.array([1., 2.5, 3.])
coeff_noise = np.array([0.5, 0.1, 0.5])
tlist_noise2 = np.array([0.5, 2, 3.])
coeff_noise2 = np.array([0.1, 0.2, 0.3])
# Pulse with different dims
random_qobj = Qobj(np.random.random((3, 3)))
pulse5 = Pulse(sigmaz(), 1, tlist, True)
pulse5.add_coherent_noise(sigmay(), 1, tlist_noise, coeff_noise)
pulse5.add_lindblad_noise(
random_qobj, 0, tlist=tlist_noise2, coeff=coeff_noise2)
qu, c_ops = pulse5.get_noisy_qobjevo(dims=[3, 2])
assert_allclose(qu.ops[0].qobj, tensor([identity(3), sigmaz()]))
assert_allclose(qu.ops[1].qobj, tensor([identity(3), sigmay()]))
assert_allclose(c_ops[0].ops[0].qobj, tensor([random_qobj, identity(2)]))
def get_noisy_dynamics(self, dims):
"""
Return a list of Pulse object with only trivial ideal pulse (H=0) but
non-trivial relaxation noise.
Parameters
----------
dims: list, optional
The dimension of the components system, the default value is
[2,2...,2] for qubits system.
Returns
-------
lindblad_noise: list of :class:`qutip.qip.Pulse`
A list of Pulse object with only trivial ideal pulse (H=0) but
non-trivial relaxation noise.
"""
if isinstance(dims, list):
for d in dims:
if d != 2:
raise ValueError(
"Relaxation noise is defined only for qubits system")
N = len(dims)
else:
N = dims
self.t1 = self._T_to_list(self.t1, N)
self.t2 = self._T_to_list(self.t2, N)
if len(self.t1) != N or len(self.t2) != N:
raise ValueError(
"Length of t1 or t2 does not match N, "
"len(t1)={}, len(t2)={}".format(
len(self.t1), len(self.t2)))
lindblad_noise = Pulse(None, None)
if self.targets is None:
targets = range(N)
else:
targets = self.targets
for qu_ind in targets:
t1 = self.t1[qu_ind]
t2 = self.t2[qu_ind]
if t1 is not None:
op = 1/np.sqrt(t1) * destroy(2)
lindblad_noise.add_lindblad_noise(op, qu_ind, coeff=True)
if t2 is not None:
# Keep the total dephasing ~ exp(-t/t2)
if t1 is not None:
if 2*t1 < t2:
raise ValueError(
"t1={}, t2={} does not fulfill "
"2*t1>t2".format(t1, t2))
T2_eff = 1./(1./t2-1./2./t1)
else:
T2_eff = t2
op = 1/np.sqrt(2*T2_eff) * sigmaz()
lindblad_noise.add_lindblad_noise(op, qu_ind, coeff=True)
return lindblad_noise
def get_noisy_dynamics(self,
dims=None,
pulses=None,
systematic_noise=None):
if systematic_noise is None:
systematic_noise = Pulse(None, None, label="system")
N = len(dims)
# time-independent
if (self.coeff is None) and (self.tlist is None):
self.coeff = True
for c_op in self.c_ops:
if self.all_qubits:
for targets in range(N):
systematic_noise.add_lindblad_noise(
c_op, targets, self.tlist, self.coeff)
else:
systematic_noise.add_lindblad_noise(c_op, self.targets,
self.tlist, self.coeff)
return pulses, systematic_noise
def TestNoisyPulse():
"""
Test for lindblad noise and different tlist
"""
coeff = np.array([0.1, 0.2, 0.3, 0.4])
tlist = np.array([0., 1., 2., 3.])
ham = sigmaz()
pulse1 = Pulse(ham, 1, tlist, coeff)
# Add coherent noise and lindblad noise with different tlist
pulse1.spline_kind = "step_func"
tlist_noise = np.array([1., 2.5, 3.])
coeff_noise = np.array([0.5, 0.1, 0.5])
pulse1.add_coherent_noise(sigmay(), 0, tlist_noise, coeff_noise)
tlist_noise2 = np.array([0.5, 2, 3.])
coeff_noise2 = np.array([0.1, 0.2, 0.3])
pulse1.add_lindblad_noise(sigmax(), 1, coeff=True)
pulse1.add_lindblad_noise(
sigmax(), 0, tlist=tlist_noise2, coeff=coeff_noise2)
assert_allclose(
pulse1.get_ideal_qobjevo(2).ops[0].qobj, tensor(identity(2), sigmaz()))
noise_qu, c_ops = pulse1.get_noisy_qobjevo(2)
assert_allclose(noise_qu.tlist, np.array([0., 0.5, 1., 2., 2.5, 3.]))
for ele in noise_qu.ops:
if ele.qobj == tensor(identity(2), sigmaz()):
assert_allclose(
ele.coeff, np.array([0.1, 0.1, 0.2, 0.3, 0.3, 0.4]))
elif ele.qobj == tensor(sigmay(), identity(2)):
assert_allclose(
ele.coeff, np.array([0., 0., 0.5, 0.5, 0.1, 0.5]))
for c_op in c_ops:
if len(c_op.ops) == 0:
assert_allclose(c_ops[0].cte, tensor(identity(2), sigmax()))
else:
assert_allclose(
c_ops[1].ops[0].qobj, tensor(sigmax(), identity(2)))
assert_allclose(
c_ops[1].tlist, np.array([0., 0.5, 1., 2., 2.5, 3.]))
assert_allclose(
c_ops[1].ops[0].coeff, np.array([0., 0.1, 0.1, 0.2, 0.2, 0.3]))
def get_noisy_dynamics(self,
dims=None,
pulses=None,
systematic_noise=None):
if systematic_noise is None:
systematic_noise = Pulse(None, None, label="system")
N = len(dims)
self.t1 = self._T_to_list(self.t1, N)
self.t2 = self._T_to_list(self.t2, N)
if len(self.t1) != N or len(self.t2) != N:
raise ValueError("Length of t1 or t2 does not match N, "
"len(t1)={}, len(t2)={}".format(
len(self.t1), len(self.t2)))
if self.targets is None:
targets = range(N)
else:
targets = self.targets
for qu_ind in targets:
t1 = self.t1[qu_ind]
t2 = self.t2[qu_ind]
if t1 is not None:
op = 1 / np.sqrt(t1) * destroy(dims[qu_ind])
systematic_noise.add_lindblad_noise(op, qu_ind, coeff=True)
if t2 is not None:
# Keep the total dephasing ~ exp(-t/t2)
if t1 is not None:
if 2 * t1 < t2:
raise ValueError("t1={}, t2={} does not fulfill "
"2*t1>t2".format(t1, t2))
T2_eff = 1. / (1. / t2 - 1. / 2. / t1)
else:
T2_eff = t2
op = 1 / np.sqrt(2 * T2_eff) * 2 * num(dims[qu_ind])
systematic_noise.add_lindblad_noise(op, qu_ind, coeff=True)
return pulses, systematic_noise