Fire Opal RIKEN Client

This is the Fire Opal client integration for RIKEN quantum computing infrastructure using a gRPC client.

Architecture Overview

• Client: Qiskit SamplerV2 implementation that sends circuits to Fire Opal server for optimization
• Server: gRPC service that performs Fire Opal preprocessing/postprocessing

Installation

Choose the version that matches where you are logged in:

• Fugaku: install the sqc version.
• R-CCS cloud: install the ibm version.

Fugaku

Complete these steps before you install:

1. Create a JHPC Quantum account. Sign up here: https://idp.qc.r-ccs.riken.jp/realms/jhpc-quantum/account
2. Set up and install your CA certificate and JWT token in your Fugaku home directory. The JWT token must be located at $HOME/.sqc_rpc_sched/jwt.token.
3. Set up your Python environment by following this guide: https://github.com/jhpc-quantum/documents/blob/main/Qiskit_JHPC_Quantum_user_guide.md

After you finish the steps above, install the sqc version:

pip install 'qctrl-fire-opal-riken-client[sqc]'

R-CCS cloud

The steps above are not required for R-CCS cloud. Install the ibm version:

pip install 'qctrl-fire-opal-riken-client[ibm]'

Usage

Here is a small example of how to use the Fire Opal RIKEN client with Qiskit. This communicates with a gRPC server to perform Fire Opal optimizations on a quantum circuit before executing it. Once the job is complete, post-processed results are returned from the job.result() call.

The only difference between Fugaku (sqc) and R-CCS cloud (ibm) is how the QiskitRuntimeService channel and backend are set up, as noted in the comments below.

from qiskit import QuantumCircuit
from fireopalrikenclient.sampler import FireOpalSampler
from qiskit_ibm_runtime import QiskitRuntimeService

# Create circuit.
circuit = QuantumCircuit(2)
circuit.h(0)
circuit.cx(0, 1)
circuit.measure_all()

# Create sampler with Fire Opal preprocessing.
#
# On Fugaku (`sqc`), use the `jhpc_quantum` channel and the `ibm_sqc` backend.
# No `token` or `instance` is needed here, since those are provided by your
# SQC environment setup.
service = QiskitRuntimeService(channel="jhpc_quantum")
sampler = FireOpalSampler(mode=service.backend("ibm_sqc"))
#
# On R-CCS cloud (`ibm`), use the `ibm_quantum_platform` channel and the
# `ibm_kobe` backend. Replace `token` and `instance` with your `ibm_kobe`
# credentials provided by RIKEN.
# service = QiskitRuntimeService(token="...", instance="...", channel="ibm_quantum_platform")
# sampler = FireOpalSampler(mode=service.backend("ibm_kobe"))

# Run circuit with 1024 shots using Fire Opal optimization.
sampler_pub = (circuit, None, 1024)
job = sampler.run([sampler_pub])
result = job.result()

# Access the results
print(f"Number of pub results: {len(result)}")
print(f"Metadata: {result.metadata}")

# Access individual pub results by iterating over the result
for i, pub_result in enumerate(result):
    print(f"Pub {i}: {pub_result}")

# Or access a single pub result directly by index
print(f"First pub result: {result[0]}")