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: int | float | integer | floating | list[int | float | integer | floating] | tuple[int | float | integer | floating, ...] | ndarray[tuple[Any, ...], dtype[floating]] | ndarray[tuple[Any, ...], dtype[integer]], tlist: ArrayLike | None = None, indices: list[int | integer] | tuple[int | integer, ...] | ndarray[tuple[Any, ...], dtype[integer]] | None = None)

Bases: Noise

The noise in the amplitude of the control pulse.

Parameters:

coeffReal | RealSequence

A list of the coefficients for the control Hamiltonians. For available choices, see qutip.QobjEvo.

tlistarray_like, optional

A NumPy array specifies the time of each coefficient.

indicesIntSequence, optional

The indices of target pulse in the list of pulses.

Attributes:

coeffReal | RealSequence

A list of the coefficients for the control Hamiltonians. For available choices, see qutip.QobjEvo.

tlistarray_like or None

A NumPy array specifies the time of each coefficient.

indicesIntSequence or None

The indices of target pulse in the list of pulses.

get_noisy_pulses(dims: list[int] | None = None, pulses: list[Pulse] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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

Parameters:

dimslist of int, optional

The dimension of the components system, the default value is [2, 2, …, 2] for qubits system.

pulseslist of Pulse, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulseslist of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.DecoherenceNoise(c_ops: Qobj | list[Qobj], targets: int | list[int | integer] | tuple[int | integer, ...] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, coeff: list[int | float | integer | floating] | tuple[int | float | integer | floating, ...] | ndarray[tuple[Any, ...], dtype[floating]] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, tlist: ArrayLike | None = None, all_qubits: bool = False)

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 of qutip.Qobj

The collapse operators representing the dynamics of the noise.

targetsint or list of int, optional

The indices of qubits that are acted on. Default is on all qubits.

coefflist of float or bool, optional

A list of the coefficients for the control Hamiltonians.

tlistarray_like, optional

A NumPy array specifies the time of each coefficient.

all_qubitsbool, optional

If c_ops contains only single qubits collapse operator, all_qubits=True will allow it to be applied to all qubits.

Attributes:

c_opslist of qutip.Qobj

The collapse operators representing the dynamics of the noise.

targetsint or list of int or None

The indices of qubits that are acted on.

coeffRealSequence or None

A list of the coefficients for the control Hamiltonians.

tlistarray_like or None

A NumPy array specifies the time of each coefficient.

all_qubitsbool

Whether the operator is applied to all qubits.

get_noisy_pulses(dims: list[int] | None = None, pulses: list[Pulse] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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

Parameters:

dimslist of int, optional

The dimension of the components system, the default value is [2, 2, …, 2] for a system of qubits.

pulseslist of Pulse, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulseslist of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.Noise

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: list[int] | None = None, pulses: list[Pulse] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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:

dimslist of int, optional

The dimension of the components system, the default value is [2, 2, …, 2] for qubits system.

pulseslist of Pulse, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulseslist of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.RandomNoise(dt: float, rand_gen: Generator, indices: list[int] | None = None, **kwargs)

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:

dtfloat

The time interval between two random amplitude. The coefficients of the noise are the same within this time range.

rand_gennumpy.random.Generator

A numpy random generator, reference numpy.random, it has to take a size parameter as the size of random numbers in the output array.

indiceslist of int, optional

The indices of target pulse in the list of pulses.

**kwargs

Key word arguments for the random number generator.

Attributes:

dtfloat

The time interval between two random amplitude. The coefficients of the noise are the same within this time range.

rand_gennumpy.random.Generator

A numpy random generator, reference numpy.random.

indiceslist of int or None

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)

get_noisy_pulses(dims: list[int] | None = None, pulses: list[Pulse] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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

Parameters:

dimslist of int, optional

The dimension of the components system, the default value is [2, 2, …, 2] for qubits system.

pulseslist of Pulse, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulseslist of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.RelaxationNoise(t1: int | float | integer | floating | list[int | float | integer | floating] | tuple[int | float | integer | floating, ...] | ndarray[tuple[Any, ...], dtype[floating]] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, t2: int | float | integer | floating | list[int | float | integer | floating] | tuple[int | float | integer | floating, ...] | ndarray[tuple[Any, ...], dtype[floating]] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, targets: int | integer | list[int | integer] | tuple[int | integer, ...] | ndarray[tuple[Any, ...], dtype[integer]] | None = None)

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: list[int | integer] | tuple[int | integer, ...] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, pulses: list[int | float | integer | floating] | tuple[int | float | integer | floating, ...] | ndarray[tuple[Any, ...], dtype[floating]] | ndarray[tuple[Any, ...], dtype[integer]] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulses: list of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

class qutip_qip.noise.ZZCrossTalk(params: dict[str, any])

Bases: Noise

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

Parameters:

paramsdict

Parameters computed from a SCQubits. Expected keys: "J", "wq_dressed_cavity", "alpha".

Attributes:

paramsdict

The device parameters used to compute ZZ coupling coefficients.

get_noisy_pulses(dims: list[int] | None = None, pulses: list[Pulse] | None = None, systematic_noise: Pulse | None = None) → tuple[list[Pulse], Pulse]

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

Parameters:

dimslist of int, optional

The dimension of the components system, the default value is [2, 2, …, 2] for qubits system.

pulseslist of Pulse, optional

The input pulses. The noise will be added to pulses in this list.

systematic_noisePulse, optional

The dummy pulse with no ideal control element.

Returns:

noisy_pulseslist of Pulse

Noisy pulses.

systematic_noisePulse

The dummy pulse representing pulse-independent noise.

qutip_qip.noise.process_noise(pulses: list[Pulse], noise_list: list[Noise], dims: int | list[int], t1: float | list[float] | None = None, t2: float | list[float] | None = None, device_noise: bool = False, spline_kind: str | None = None) → list[Pulse]

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 of :class:`.Pulse`

The input pulses, on which the noise object will be applied.

noise_list: list of :class:`.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.

spline_kind: str, optional

Type of the coefficient interpolation: “step_func” or “cubic”.

Returns:

noisy_pulses: list of Pulse

The noisy pulses, including the system noise.