Quantum Processing Unit (QPU)

A Quantum Processing Unit (or QPU) is, in this framework, a Python object designed to execute a Job and return a Result:

• The Job defines what should be executed (e.g. quantum circuit, analog schedule, annealing Ising Hamiltonian), how to execute it (e.g. initial state, number of shots), and which information should be returned to the user (e.g. final measurement, aggregate data). The definition of a Job is presented on the job page.

• The Result contains the output of the execution, such as measurement outputs (e.g. list of samples, average value of an Observable), and, optionally, some information on the execution (contained in the meta-data of the Result). The definition of Result is presented on the result page.

A QPU can be a Quantum Emulator (a classical software emulating the behavior of a physical QPU) or a Physical system. Our framework defines 3 types of QPUs, which are:

• Gate based QPUs: These QPUs execute a job containing a circuit. The Circuit is wrapped into a job by using the respective to_job() method.

• Analog QPUs: These QPUs execute a job containing a schedule. The Schedule is wrapped into a job by using the respective to_job() method.

• Annealing QPUs: These QPUs execute a job containing an Ising Hamiltonian. The Ising is wrapped into a job by using the respective to_job() method.

from qat.qpus import CLinalg

# Define a PORT and a IP
PORT = 1234
IP = "*"

# Define a QPU
qpu = CLinalg()
qpu.serve(PORT, IP)

from qat.qpus import RemoteQPU

# Define PORT and IP
PORT = 1234
IP = "127.0.0.1"

# Define a client
qpu = RemoteQPU(PORT, IP)