QunaSys Inc. (Headquarters: Bunkyo-ku, Tokyo; CEO: Tennin Yan; hereinafter “QunaSys”), a company specializing in quantum computing software and algorithm development, announced the launch of a dedicated QSCI technical portal and an official partner program for hardware vendors, marking the next phase in the commercial expansion of its proprietary algorithm, Quantum-Selected Configuration Interaction (QSCI).
Originally published in February 2023 (arXiv: 2302.11320), QSCI has evolved from a research breakthrough into a commercially deployable methodology within quantum–HPC hybrid environments.

Unlocking the Full Potential of Quantum Hardware

QSCI was developed to address a core limitation of NISQ-era quantum computing: the gap between available qubit counts and the number of qubits that can be meaningfully utilized in practice.
While conventional approaches such as VQE often struggle to scale due to noise and precision constraints, QSCI combines:

• Quantum-native sampling
• Large-scale classical matrix computation

This hybrid architecture enables significantly larger and more realistic problem instances to be executed on real quantum devices.
QSCI-based approaches have been utilized in initiatives involving RIKEN and IBM, including hybrid demonstrations combining the Fugaku supercomputer and IBM quantum processors.
Today, QSCI is being applied beyond quantum chemistry to optimization and other computationally intensive domains.


This figure illustrates the growth in the number of qubits validated on actual quantum hardware.Recent progress in both hardware performance and algorithmic design has expanded the size of problems that can be validated on physical quantum systems.Compared to conventional methods, QSCI has enabled larger-scale demonstrations on real devices, helping push quantum computing closer to practical industrial applications.

Building a Global QSCI Ecosystem

Since its introduction, QSCI has become a foundation for a growing body of international research and development.
Key areas of expansion include:

• Advanced state preparation techniques
• Noise resilience strategies
• Subspace construction optimization
• Hybridization with AFQMC and perturbative methods

Recent publications from Keio University, QunaSys, and IBM on time-evolution-based state preparation further highlight the global momentum surrounding QSCI.
To consolidate this expanding knowledge base, QunaSys has launched the QSCI Technical Portal (“Awesome QSCI”).
The portal provides companies evaluating QSCI adoption with a structured overview of the technology’s evolution, maturity, and ecosystem development. It also clarifies the distinction between QSCI and SQD (Sample-based Quantum Diagonalization).
Learn more:
https://awesome-qsci.qunasys.com/

Official Partner Program for Hardware Vendors

As QSCI moves into broader commercial deployment, practical challenges remain, including hardware-specific optimization, IP structuring, and enterprise onboarding complexity.
To accelerate real-world adoption, QunaSys has launched an official partner program for quantum hardware vendors.
The program offers:
Joint Technical Optimization
Collaboration on performance tuning and next-generation hardware alignment
Enterprise Implementation Support
Official recommendation of certified hardware to QPARC and other enterprise customers
Comprehensive IP Framework
Structured sublicensing to streamline commercial integration
Global Co-Marketing
Joint announcements and roadmap communication to increase market visibility
QSCI integration provides hardware vendors with a concrete, high-value use case that demonstrates system capability and supports market differentiation.

CEO Comment

“Quantum computing will not reach industrial impact through hardware advances alone,” said Tennin Yan, CEO of QunaSys. “Algorithms that fully leverage hardware capabilities are equally essential. QSCI represents a key milestone in that direction.
Our ambition is to accelerate chemical R&D by 10 to 100 times. We are clear-eyed about current limitations, and we remain committed to overcoming the remaining barriers to real-world quantum advantage.”

Moving Forward

QSCI has transitioned from research innovation to commercial ecosystem development.
QunaSys is actively prioritizing collaboration with forward-looking hardware vendors and enterprise partners ready to explore early-stage deployment.
For partnership inquiries or enterprise collaboration:
Hardware Vendors – Official Partner Program
Enterprises – QSCI-based PoC and implementation support
Contact:
pr@qunasys.com