Note
This is the documentation for the current state of the development branch of Qiskit Experiments. The documentation or APIs here can change prior to being released.
PulseBackend¶
- class PulseBackend(static_hamiltonian, hamiltonian_operators, static_dissipators=None, dt=1.0000000000000002e-10, solver_method='RK23', seed=0, atol=None, rtol=None, **kwargs)[source]¶
Abstract base class for pulse simulation backends in Qiskit Experiments.
This backend is designed for the tests in Qiskit Experiments as well as for the tutorials in Qiskit Experiments. The backend has a Qiskit Dynamics pulse simulator which allows it to simulate pulse schedules that are included in the calibrations attached to quantum circuits. In addition, sub-classes should implement a set of default schedules so that circuits that do not provide calibrations can also run, much like the hardware backends. In addition, the backends are also capable of simulating level- one (IQ data) and level-two (counts) data. Subclasses of these backends can have an optional discriminator so that they can produce counts based on sampled IQ data. If a discriminator is not provided then the counts will be produced from a statevector or density matrix.
Warning
Some of the functionality in this backend may move to Qiskit Dynamics and/or be refactored. These backends are not intended as a general pulse-simulator backend but rather to test the experiments and write short tutorials to demonstrate an experiment without having to run on hardware.
Initialize a backend with model information.
- Parameters:
static_hamiltonian (ndarray) – Time-independent term in the Hamiltonian.
hamiltonian_operators (ndarray) – List of time-dependent operators
static_dissipators (ndarray | None) – Constant dissipation operators. Defaults to None.
dt (float) – Sample rate for simulating pulse schedules. Defaults to 0.1*1e-9.
solver_method – Numerical solver method to use. Check qiskit_dynamics for available methods. Defaults to “RK23”.
seed (int) – An optional seed given to the random number generator. If this argument is not set then the seed defaults to 0.
atol (float) – Absolute tolerance during solving.
rtol (float) – Relative tolerance during solving.
Attributes
- coupling_map¶
Return the
CouplingMap
object
- default_pulse_unitaries¶
Return the default unitary matrices of the backend.
- discriminator¶
Return the discriminator for the IQ data.
- dt¶
Return the system time resolution of input signals
This is required to be implemented if the backend supports Pulse scheduling.
- Returns:
The input signal timestep in seconds. If the backend doesn’t define
dt
,None
will be returned.
- dtm¶
Return the system time resolution of output signals
- Returns:
The output signal timestep in seconds.
- Raises:
NotImplementedError – if the backend doesn’t support querying the output signal timestep
- instruction_durations¶
Return the
InstructionDurations
object.
- instruction_schedule_map¶
Return the
InstructionScheduleMap
for the instructions defined in this backend’s target.
- instructions¶
A list of Instruction tuples on the backend of the form
(instruction, (qubits)
- max_circuits¶
- meas_map¶
Return the grouping of measurements which are multiplexed
This is required to be implemented if the backend supports Pulse scheduling.
- Returns:
The grouping of measurements which are multiplexed
- Raises:
NotImplementedError – if the backend doesn’t support querying the measurement mapping
- num_qubits¶
Return the number of qubits the backend has.
- operation_names¶
A list of instruction names that the backend supports.
- operations¶
A list of
Instruction
instances that the backend supports.
- options¶
Return the options for the backend
The options of a backend are the dynamic parameters defining how the backend is used. These are used to control the
run()
method.
- provider¶
Return the backend Provider.
- Returns:
the Provider responsible for the backend.
- Return type:
Provider
- target¶
Contains information for circuit transpilation.
- version = 2¶
- description¶
Optional human-readable description.
- online_date¶
Date that the backend came online.
- backend_version¶
Version of the backend being provided. This is not the same as
BackendV2.version
, which is the version of theBackend
abstract interface.
Methods
- acquire_channel(qubit)¶
Return the acquisition channel for the given qubit.
This is required to be implemented if the backend supports Pulse scheduling.
- Returns:
The Qubit measurement acquisition line.
- Return type:
AcquireChannel
- Raises:
NotImplementedError – if the backend doesn’t support querying the measurement mapping
- control_channel(qubits)¶
Return the secondary drive channel for the given qubit
This is typically utilized for controlling multiqubit interactions. This channel is derived from other channels.
This is required to be implemented if the backend supports Pulse scheduling.
- Parameters:
qubits (Iterable[int]) – Tuple or list of qubits of the form
(control_qubit, target_qubit)
.- Returns:
The multi qubit control line.
- Return type:
List[ControlChannel]
- Raises:
NotImplementedError – if the backend doesn’t support querying the measurement mapping
- drive_channel(qubit)¶
Return the drive channel for the given qubit.
This is required to be implemented if the backend supports Pulse scheduling.
- Returns:
The Qubit drive channel
- Return type:
DriveChannel
- Raises:
NotImplementedError – if the backend doesn’t support querying the measurement mapping
- measure_channel(qubit)¶
Return the measure stimulus channel for the given qubit.
This is required to be implemented if the backend supports Pulse scheduling.
- Returns:
The Qubit measurement stimulus line
- Return type:
MeasureChannel
- Raises:
NotImplementedError – if the backend doesn’t support querying the measurement mapping
- qubit_properties(qubit)¶
Return QubitProperties for a given qubit.
If there are no defined or the backend doesn’t support querying these details this method does not need to be implemented.
- Parameters:
qubit (int | List[int]) – The qubit to get the
QubitProperties
object for. This can be a single integer for 1 qubit or a list of qubits and a list ofQubitProperties
objects will be returned in the same order- Returns:
The
QubitProperties
object for the specified qubit. If a list of qubits is provided a list will be returned. If properties are missing for a qubit this can beNone
.- Raises:
NotImplementedError – if the backend doesn’t support querying the qubit properties
- Return type:
QubitProperties | List[QubitProperties]
- run(run_input, **run_options)[source]¶
Run method takes circuits as input and returns FakeJob with IQ data or counts.
- Parameters:
run_input (QuantumCircuit | List[QuantumCircuit]) – Circuits to run.
run_options – Any option that affects the way that the circuits are run. The options that are currently supported are
shots
,meas_level
,meas_return
, andmemory
.
- Returns:
FakeJob with simulation data.
- Return type:
FakeJob
- set_options(**fields)¶
Set the options fields for the backend
This method is used to update the options of a backend. If you need to change any of the options prior to running just pass in the kwarg with the new value for the options.
- Parameters:
fields – The fields to update the options
- Raises:
AttributeError – If the field passed in is not part of the options
- solve(schedule, qubits)[source]¶
Solves for qubit dynamics under the action of a pulse instruction
- Parameters:
schedule (ScheduleBlock | Schedule) – Pulse signal
qubits (Tuple[int]) – (remove after multi-qubit gates is implemented)
- Returns:
Time-evolution unitary operator
- Return type:
ndarray