Hardware and cloud

Using Strawberry Fields, you can submit quantum programs to be executed on photonic hardware or to be run on a cloud simulator via the Xanadu Cloud.

Warning

An API key is required to access the Xanadu Cloud platform. If you do not have a Xanadu Cloud API key, you can request hardware access via the sign up form on the Xanadu website.

Configuring your account

Before using the Xanadu Cloud platform, you will need to configure your credentials using the Xanadu Cloud Client. The simplest way to do this is through the xcc config command line interface:

$ xcc config set REFRESH_TOKEN "Xanadu Cloud API key goes here"

You can verify that your account credentials successfully authenticate against the Xanadu Cloud platform by running

$ xcc ping
Successfully connected to the Xanadu Cloud.

Submitting jobs on hardware

Once connected to the Xanadu cloud platform, the Strawberry Fields RemoteEngine can be used to submit quantum programs to available photonic hardware:

>>> eng = sf.RemoteEngine("chip_name")
>>> result = eng.run(prog)

In the above example, eng.run() is a blocking method; Python will wait until the job result has been returned from the cloud before further lines will execute.

Jobs can also be submitted using the non-blocking eng.run_async() method. Unlike eng.run(), which returns a Result object once the computation is complete, this method instead returns a xcc.Job object directly that can be queried to get the job’s status.

>>> job = engine.run_async(prog, shots=3)
>>> job.status
"queued"
>>> job.wait()
>>> job.status
"complete"
>>> result = sf.Result(job.result)
>>> result.samples
array([[0, 0, 1, 0, 1, 0, 1, 0],
       [0, 0, 0, 0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0, 0, 0, 2]])

Further details on the xcc.Job class can be found in the Xanadu Cloud Client documentation.

Alternatively, if you have your quantum program available as a Blackbird script, you can submit the Blackbird script file to be executed remotely using the Xanadu Cloud Client command line interface:

$ xcc job submit \
    --name "example" \
    --target "X8_01" \
    --language "blackbird:1.0" \
    --circuit "name example\nversion 1.0\ntarget X8_01 (shots=3)\n ..."

Cloud simulator

In addition to submitting jobs to be run on quantum hardware, it is also possible to run jobs on cloud simulators (which we refer to as “simulons”) via the Xanadu Quantum Cloud. The process is very similar to running jobs on hardware. You will need to configure your account, as described above, and submit a job via the RemoteEngine, using a simulator as the target instead of a specific chip:

>>> eng = sf.RemoteEngine("simulon_gaussian")
>>> result = eng.run(prog)

Simulator jobs can also be submitted asynchronously using eng.run_async, or by submitting a Blackbird script with the target set to a simulator target in the Blackbird header.

See the Submitting jobs on hardware section above for more details.

Note

The simulon_gaussian simulator runs on the gaussian backend (see Simulating your program) and thus only supports Gaussian operations, including homodyne and heterodyne measurements, as well terminal Fock measurements. Note that there are limits to how many measurements a circuit can have depending on the type of measurement. These can be retrieved by calling engine.device_spec.modes with engine = sf.RemoteEngine("simulon_gaussian").

Tutorials

For more details on submitting jobs to photonic hardware, check out the following tutorials.