UnitarySimulator

class UnitarySimulator(configuration=None, properties=None, provider=None, **backend_options)

Bases: qiskit.providers.aer.backends.aerbackend.AerBackend

Ideal quantum circuit unitary simulator.

Configurable Options

The UnitarySimulator supports CPU and GPU simulation methods and additional configurable options. These may be set using the appropriate kwargs during initialization. They can also be set of updated using the set_options() method.

Run-time options may also be specified as kwargs using the run() method. These will not be stored in the backend and will only apply to that execution. They will also override any previously set options.

For example, to configure a a single-precision simulator

backend = UnitarySimulator(precision='single')

Backend Options

The following configurable backend options are supported

device (str): Set the simulation device (Default: "CPU"). Use available_devices() to return a list of devices supported on the current system.
method (str): [DEPRECATED] Set the simulation method supported methods are "unitary" for CPU simulation, and "unitary_gpu" for GPU simulation. This option has been deprecated, use the device option to set “CPU” or “GPU” simulation instead.
precision (str): Set the floating point precision for certain simulation methods to either "single" or "double" precision (default: "double").
executor (futures.Executor): Set a custom executor for asynchronous running of simulation jobs (Default: None).
max_shot_size (int or None): If the number of shots of a noisy circuit exceeds this value simulation will be split into multi circuits for execution and the results accumulated. If None circuits will not be split based on shots. When splitting circuits use the max_job_size option to control how these split circuits should be submitted to the executor (Default: None).
max_shot_size (int or None): If the number of shots with a noise model exceeds this value, simulation will split the experiments into sub experiments in the qobj. If None simulator does nothing (Default: None).
"initial_unitary" (matrix_like): Sets a custom initial unitary matrix for the simulation instead of identity (Default: None).
"validation_threshold" (double): Sets the threshold for checking if initial unitary and target unitary are unitary matrices. (Default: 1e-8).
"zero_threshold" (double): Sets the threshold for truncating small values to zero in the result data (Default: 1e-10).
"max_parallel_threads" (int): Sets the maximum number of CPU cores used by OpenMP for parallelization. If set to 0 the maximum will be set to the number of CPU cores (Default: 0).
"max_parallel_experiments" (int): Sets the maximum number of qobj experiments that may be executed in parallel up to the max_parallel_threads value. If set to 1 parallel circuit execution will be disabled. If set to 0 the maximum will be automatically set to max_parallel_threads (Default: 1).
"max_memory_mb" (int): Sets the maximum size of memory to store a state vector. If a state vector needs more, an error is thrown. In general, a state vector of n-qubits uses 2^n complex values (16 Bytes). If set to 0, the maximum will be automatically set to the system memory size (Default: 0).
"statevector_parallel_threshold" (int): Sets the threshold that 2 * “n_qubits” must be greater than to enable OpenMP parallelization for matrix multiplication during execution of an experiment. If parallel circuit or shot execution is enabled this will only use unallocated CPU cores up to max_parallel_threads. Note that setting this too low can reduce performance (Default: 14).

These backend options apply in circuit optimization passes:

fusion_enable (bool): Enable fusion optimization in circuit optimization passes [Default: True]
fusion_verbose (bool): Output gates generated in fusion optimization into metadata [Default: False]
fusion_max_qubit (int): Maximum number of qubits for a operation generated in a fusion optimization [Default: 5]
fusion_threshold (int): Threshold that number of qubits must be greater than or equal to enable fusion optimization [Default: 7]

Aer class for backends.

This method should initialize the module and its configuration, and raise an exception if a component of the module is not available.

Parameters

configuration (BackendConfiguration) – backend configuration.
properties (BackendProperties or None) – Optional, backend properties.
defaults (PulseDefaults or None) – Optional, backend pulse defaults.
provider (Provider) – Optional, provider responsible for this backend.
backend_options (dict or None) – Optional set custom backend options.

Raises

AerError – if there is no name in the configuration

Methods

available_devices

UnitarySimulator.available_devices()

Return the available simulation methods.

available_methods

UnitarySimulator.available_methods()

Return the available simulation methods.

clear_options

UnitarySimulator.clear_options()

Reset the simulator options to default values.

configuration

UnitarySimulator.configuration()

Return the simulator backend configuration.

Returns

the configuration for the backend.

Return type

BackendConfiguration

defaults

UnitarySimulator.defaults()

Return the simulator backend pulse defaults.

Returns

The backend pulse defaults or None if the

backend does not support pulse.

Return type

PulseDefaults

name

UnitarySimulator.name()

Return the backend name.

Returns

the name of the backend.

Return type

str

properties

UnitarySimulator.properties()

Return the simulator backend properties if set.

Returns

The backend properties or None if the

backend does not have properties set.

Return type

BackendProperties

provider

UnitarySimulator.provider()

Return the backend Provider.

Returns

the Provider responsible for the backend.

Return type

Provider

run

UnitarySimulator.run(circuits, validate=False, parameter_binds=None, **run_options)

Run a qobj on the backend.

Parameters

circuits (QuantumCircuit or list) – The QuantumCircuit (or list of QuantumCircuit objects) to run
validate (bool) – validate the Qobj before running (default: False).
parameter_binds (list) – A list of parameter binding dictionaries. See additional information (default: None).
run_options (kwargs) – additional run time backend options.

Returns

The simulation job.

Return type

AerJob

Raises

AerError – If parameter_binds is specified with a qobj input or has a length mismatch with the number of circuits.

Additional Information:

Each parameter binding dictionary is of the form:
```
{
    param_a: [val_1, val_2],
    param_b: [val_3, val_1],
}
```
for all parameters in that circuit. The length of the value list must be the same for all parameters, and the number of parameter dictionaries in the list must match the length of circuits (if circuits is a single QuantumCircuit object it should a list of length 1).
kwarg options specified in run_options will temporarily override any set options of the same name for the current run.

Raises

ValueError – if run is not implemented

set_option

UnitarySimulator.set_option(key, value)

Special handling for setting backend options.

This method should be extended by sub classes to update special option values.

Parameters

key (str) – key to update
value (any) – value to update.

Raises

AerError – if key is ‘method’ and val isn’t in available methods.

set_options

UnitarySimulator.set_options(**fields)

Set the simulator options

status

UnitarySimulator.status()

Return backend status.

Returns

the status of the backend.

Return type

BackendStatus

Attributes

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.

version

Default value: 1

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