qutip_qip.noise

Noise of quantum hardware.

Classes

`Noise`()	The base class representing noise in a processor.
`ControlAmpNoise`(coeff[, tlist, indices])	The noise in the amplitude of the control pulse.
`RelaxationNoise`([t1, t2, targets])	The decoherence on each qubit characterized by two time scales t1 and t2.
`DecoherenceNoise`(c_ops[, targets, coeff, ...])	The decoherence noise in a processor.
`RandomNoise`(dt, rand_gen[, indices])	Random noise in the amplitude of the control pulse.
`ZZCrossTalk`(params)	An always-on ZZ cross talk noise with the corresponding coefficient on each pair of qubits.

class qutip_qip.noise.ControlAmpNoise(coeff, tlist=None, indices=None)[source]

Bases: Noise

The noise in the amplitude of the control pulse.

Parameters

coeff: list: A list of the coefficients for the control Hamiltonians. For available choices, see qutip.QobjEvo.
tlist: array_like, optional: A NumPy array specifies the time of each coefficient.
indices: list of int, optional: The indices of target pulse in the list of pulses.

Attributes

coeff: list: A list of the coefficients for the control Hamiltonians. For available choices, see qutip.QobjEvo.
tlist: array_like: A NumPy array specifies the time of each coefficient.
indices: list of int: The indices of target pulse in the list of pulses.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object. This is a template method, a method with the same name and signatures needs to be defined in the subclasses.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2,2…,2] for qubits system.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.DecoherenceNoise(c_ops, targets=None, coeff=None, tlist=None, all_qubits=False)[source]

Bases: Noise

The decoherence noise in a processor. It generates lindblad noise according to the given collapse operator c_ops.

Parameters

c_opsqutip.Qobj or list: The Hamiltonian representing the dynamics of the noise.
targets: int or list, optional: The indices of qubits that are acted on. Default is on all qubits
coeff: list, optional: A list of the coefficients for the control Hamiltonians.
tlist: array_like, optional: A NumPy array specifies the time of each coefficient.
all_qubits: bool, optional: If c_ops contains only single qubits collapse operator, all_qubits=True will allow it to be applied to all qubits.

Attributes

c_opsqutip.Qobj or list: The Hamiltonian representing the dynamics of the noise.
targets: int or list: The indices of qubits that are acted on.
coeff: list: A list of the coefficients for the control Hamiltonians.
tlist: array_like: A NumPy array specifies the time of each coefficient.
all_qubits: bool: If c_ops contains only single qubits collapse operator, all_qubits=True will allow it to be applied to all qubits.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2, 2, …, 2] for a system of qubits.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.Noise[source]

Bases: object

The base class representing noise in a processor. The noise object can be added to device.Processor and contributes to evolution.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object. This is a template method, a method with the same name and signatures needs to be defined in the subclasses.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2,2…,2] for qubits system.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.RandomNoise(dt, rand_gen, indices=None, **kwargs)[source]

Bases: ControlAmpNoise

Random noise in the amplitude of the control pulse. The arguments for the random generator need to be given as key word arguments.

Parameters

dt: float, optional: The time interval between two random amplitude. The coefficients of the noise are the same within this time range.
rand_gen: numpy.random, optional: A random generator in numpy.random, it has to take a size parameter as the size of random numbers in the output array.
indices: list of int, optional: The indices of target pulse in the list of pulses.
**kwargs:: Key word arguments for the random number generator.

Examples

>>> gaussnoise = RandomNoise(             dt=0.1, rand_gen=np.random.normal, loc=mean, scale=std)             

Attributes

dt: float, optional: The time interval between two random amplitude. The coefficients of the noise are the same within this time range.
rand_gen: numpy.random, optional: A random generator in numpy.random, it has to take a size parameter.
indices: list of int: The indices of target pulse in the list of pulses.
**kwargs:: Key word arguments for the random number generator.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2,2…,2] for qubits system.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.RelaxationNoise(t1=None, t2=None, targets=None)[source]

Bases: Noise

The decoherence on each qubit characterized by two time scales t1 and t2.

Parameters

t1: float or list, optional: Characterize the decoherence of amplitude damping for each qubit.
t2: float or list, optional: Characterize the decoherence of dephasing for each qubit.
targets: int or list, optional: The indices of qubits that are acted on. Default is on all qubits

Attributes

t1: float or list: Characterize the decoherence of amplitude damping for each qubit.
t2: float or list: Characterize the decoherence of dephasing for each qubit.
targets: int or list: The indices of qubits that are acted on.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2,2…,2] for qubits system.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.ZZCrossTalk(params)[source]

Bases: Noise

An always-on ZZ cross talk noise with the corresponding coefficient on each pair of qubits. The operator acts only one the lowerest two levels and is 0 on higher level. Equivalent to tensor(sigmaz(), sigmaz()).

Parameters

params:: Parameters computed from a SCQubits.

get_noisy_pulses(dims=None, pulses=None, systematic_noise=None)[source]

Return the input pulses list with noise added and the pulse independent noise in a dummy Pulse object.

Parameters

dims: list, optional: The dimension of the components system, the default value is [2,2…,2] for qubits system.
pulseslist of Pulse: The input pulses. The noise will be added to pulses in this list.
systematic_noisePulse: The dummy pulse with no ideal control element.

Returns

noisy_pulses: list ofclass:.Pulse: Noisy pulses.
systematic_noisePulse: The dummy pulse representing pulse-independent noise.

qutip_qip.noise.process_noise(pulses, noise_list, dims, t1=None, t2=None, device_noise=False, spline_kind=None)[source]

Apply noise to the input list of pulses. It does not modify the input pulse, but return a new one containing the noise.

Parameters

pulses: list ofclass:.Pulse: The input pulses, on which the noise object will be applied.
noise_list: list ofclass:.Noise: A list of noise objects.
dims: int or list: Dimension of the system. If int, we assume it is the number of qubits in the system. If list, it is the dimension of the component systems.
t1: float or list, optional: Characterize the decoherence of amplitude damping for each qubit. A list of size N or a float for all qubits.
t2: float or list, optional: Characterize the decoherence of dephasing for each qubit. A list of size N or a float for all qubits.
device_noise: bool: If pulse independent noise such as relaxation are included. Default is False.

Returns

noisy_pulses: list ofclass:.Pulse: The noisy pulses, including the system noise.