OQTOPUS Cloud

Uses cloud quantum computers and simulators available via OQTOPUS Cloud for circuit evaluation.

Available as OqtopusClient.

Note

Only OQTOPUS Cloud instances reachable with quri-parts-oqtopus==1.0.3 are supported.

An OQTOPUS Cloud API token and endpoint URL are required.

Hint

OqtopusClient was added in Amplify Quantum v1.3. If you are using an older package version, run the following command to upgrade to the latest version.

$ pip install -U 'amplify[quantum]'

Solver specification:

Client class	amplify.OqtopusClient
Execution parameters	Depends on the algorithm
Execution result	Depends on the algorithm
Execution time	Depends on the algorithm
Quantum computer type	Gate-based
API method	REST API (OQTOPUS Cloud)

The variable types and polynomial degree accepted for the input problem depend on the chosen algorithm.

• When QAOA is specified as the client argument

  	Binary	Ising	Integer	Real
  Objective function	-	Nth degree*	-	-
  Equality constraint	-	**	-	-
  Inequality constraint	-	-	-	-

  *: Problems of arbitrary degree are supported. However, depending on the qubit connectivity of the quantum computer, the required number of qubits may increase.

  **: When Constrained QAOA is selected via QAOA type, N-HOT constraints are supported.

• When RQAOA is specified as the client argument

  	Binary	Ising	Integer	Real
  Objective function	-	Nth degree*	-	-
  Equality constraint	-	-	-	-
  Inequality constraint	-	-	-	-

  *: Problems of arbitrary degree are supported. However, depending on the qubit connectivity of the quantum computer, the required number of qubits may increase.

Client class:

In addition to the common client interface, it has the following attributes.

Attribute	Data type	Details
token	str | None	The OQTOPUS API token.
url	str | None	The endpoint URL of the OQTOPUS service.
proxy	str | None	The proxy server URL used when connecting.
provider	quri_parts_oqtopus.backend.OqtopusConfig | None	Use a quri_parts_oqtopus.backend.OqtopusConfig to set authentication information instead of the token / url / proxy attributes. The provider attribute takes precedence over the others.
device	str | None	The OQTOPUS device name on which the circuit will be executed. If None, a device is chosen automatically from those available that satisfy the circuit’s qubit count.
qiskit_pass_manager	qiskit.transpiler.PassManager | EllipsisType | None	The Qiskit qiskit.transpiler.PassManager used to transpile the circuit. With the default (...), one is generated automatically by generate_preset_pass_manager. Set this to None to skip transpilation.
name	str | None	The name attached to the job submitted to OQTOPUS.
description	str | None	The description attached to the job submitted to OQTOPUS.
transpiler_info	dict | None	Transpiler information forwarded to OQTOPUS.
simulator_info	dict | None	Simulator information forwarded to OQTOPUS.
mitigation_info	dict | None	Error mitigation settings forwarded to OQTOPUS.
job_type	str | None	The job type forwarded to OQTOPUS.

Backend-specific metadata:

Detailed sampling information is available via QAOA’s sampling_meta.

meta = client_result.history[0].sampling_meta
meta.circuit             # The executed Qiskit circuit object (before transpilation)
meta.transpiled_circuit  # The circuit after transpilation (None if not transpiled)

Configuration example:

from amplify import QAOA, OqtopusClient

# Create the client
client = OqtopusClient(QAOA)

# Set the endpoint URL and API token
client.url = "<URL>"
client.token = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

# Set QAOA parameters
client.parameters.reps = 1
client.parameters.shots = 100

A quri_parts_oqtopus.backend.OqtopusConfig can also be passed directly. In this case, authentication is performed using only the value of provider.

from quri_parts_oqtopus.backend import OqtopusConfig

client = OqtopusClient(QAOA)
client.provider = OqtopusConfig.from_file()

Execution example:

from amplify import Model, VariableGenerator, solve

# Create decision variables and the objective function
g = VariableGenerator()
q = g.array("Binary", 2)
f = q[0] * q[1] + q[0] - q[1] + 1

# Create a model
model = Model(f)

# Run the solver
result = solve(model, client)

Obtain the backend version (quri-parts-oqtopus version):

>>> client.version()