qiskit.providers.aer.UnitarySimulator¶

class UnitarySimulator(configuration=None, properties=None, provider=None, **backend_options)[source]¶

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

method (str): Set the simulation method supported methods are "unitary" for CPU simulation, and "unitary_gpu" for GPU simulation (Default: "unitary").
precision (str): Set the floating point precision for certain simulation methods to either "single" or "double" precision (default: "double").
"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.
available_methods (list or None) – Optional, the available simulation methods if backend supports multiple methods.
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

__init__(configuration=None, properties=None, provider=None, **backend_options)[source]¶

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.
available_methods (list or None) – Optional, the available simulation methods if backend supports multiple methods.
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

`__init__`([configuration, properties, provider])	Aer class for backends.
`available_methods`()	Return the available simulation methods.
`clear_options`()	Reset the simulator options to default values.
`configuration`()	Return the simulator backend configuration.
`defaults`()	Return the simulator backend pulse defaults.
`name`()	Return the backend name.
`properties`()	Return the simulator backend properties if set.
`provider`()	Return the backend Provider.
`run`(circuits[, backend_options, validate])	Run a qobj on the backend.
`set_option`(key, value)	Special handling for setting backend options.
`set_options`(**fields)	Set the options fields for the backend
`status`()	Return backend status.

Attributes

`options`	Return the options for the backend
`version`

available_methods()¶: Return the available simulation methods.

clear_options()¶: Reset the simulator options to default values.

configuration()¶

Return the simulator backend configuration.

Returns: the configuration for the backend.
Return type: BackendConfiguration

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()¶

Return the backend name.

Returns: the name of the backend.
Return type: str

property 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.

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()¶

Return the backend Provider.

Returns: the Provider responsible for the backend.
Return type: Provider

run(circuits, backend_options=None, validate=False, **run_options)¶

Run a qobj on the backend.

Parameters

circuits (QuantumCircuit or list) – The QuantumCircuit (or list of QuantumCircuit objects) to run
backend_options (dict or None) – DEPRECATED dictionary of backend options for the execution (default: None).
validate (bool) – validate the Qobj before running (default: False).
run_options (kwargs) – additional run time backend options.

Returns

The simulation job.

Return type

AerJob

Additional Information:

kwarg options specified in run_options will temporarily override any set options of the same name for the current run.
The entries in the backend_options will be combined with the Qobj.config dictionary with the values of entries in backend_options taking precedence. This kwarg is deprecated and direct kwarg’s should be used for options to pass them to run_options.

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(**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

status()¶

Return backend status.

Returns: the status of the backend.
Return type: BackendStatus