On Monday, July 28, 2025, a purely domestic quantum computer will begin operation at the Center for Quantum Information and Quantum Biology (QIQB), the University of Osaka.
This new device was developed by a collaborative research group including Vice Director/Professor Makoto Negoro at QIQB of the University of Osaka, Yasunobu Nakamura, Director at RIKEN Center for Quantum Computing (RQC), Managing Executive Officer Junya Kiyota of ULVAC, Inc., Masamichi Saitoh, Counselor of ULVAC Cryogenics Incorporated, Takefumi Miyoshi, Director of e-trees.Japan, inc., CEO Yosuke Ito of QuEL, Inc., CTO Tennin Yan of QunaSys Inc., Ryo Uchida, Supervisor of Systems Engineering Consultants (SEC), Yasuhito Takamiya, Technical Expert of TIS Inc., and Shintaro Sato, Head of Quantum Laboratory, Fujitsu Research, Fujitsu Limited.
In this study, the researchers succeeded in developing a quantum computer entirely from domestically sourced technologies, including the dilution refrigerator, control device, superconducting qubit chips, and quantum cloud software. This proves that Japan possesses all the technologies necessary to build its own quantum computers and can integrate them into a system. Quantum computers have the potential to make a significant contribution to reducing environmental burden globally through the discovery of new materials and drugs, and optimization as well as some useful technologies for everyday lives, such as machine learning. The results of this research will be a first step to pave the way for a new future.
Additionally, parts of this new system will be on display at the special exhibition "entangled moment - [quantum | earth | universe] x art," at Expo 2025 Osaka, Kansai, Japan from August 14 to August 20. In this exhibition, visitors will be connected to the system via the cloud using terminals set in the venue and operate simple quantum programs to experience quantum computing. Regardless of the specialized knowledge, a wide range of people will be able to enjoy quantum technologies such as quantum entanglement.
Prior to this event, a pre-Expo exhibition and experience session will be held from 3:00 p.m. on July 28 for quantum researchers, engineers and quantum industry professionals. This is one of the satellite workshops of the international symposium "Quantum Innovation 2025," which will be held from July 29 and multiple visitors can simultaneously experience the operation of up to four qubits.
Fig. 1: Installation of the domestically made quantum computer
Credit: Makoto Negoro
About the "entangled moment - [quantum | earth | universe] x art," at Expo 2025 and the University of Osaka's exhibition
The special exhibition "entangled moment - [quantum | earth | universe] x art," is a limited-time special event held at the Expo Exhibition Center "WASSE" at Expo 2025 Osaka, Kansai, Japan from August 14 to August 20. This event is held to commemorate the International Year of Quantum Science and Technology (IYQ), and aims to provide visitors with experiences based on three themes of the world of quantum mechanics, the ocean and the earth that nurture our lives, and the vast universe, through a collaboration of science, technology, and art, and the University of Osaka will present an exhibition using quantum computers.
By using this new quantum computer, visitors can learn how to operate a quantum computer by connecting it through regular iPads placed at the venue. When commands are sent from the iPad, they are converted by the open-source quantum cloud software OQTOPUS and sent over the Internet to the University of Osaka, and a control signal is generated from the control device based on the information. Creation of the exhibition booth for those parts was led by QIQB with the cooperation of various companies. The exhibition will clearly show how a signal travels from the iPad to the University of Osaka through a refrigerator and then to the qubit. In addition, a quantum theory learning app will be connected online to the new quantum computer as the Quantum Online App Experience, allowing visitors to experience the quantum computer through the app. This app allows visitors to enjoy learning quantum theory by competing the speed and proficiency of erasing quantum gates, which are commands from quantum computers, and even those who are not familiar with quantum theory can enjoy it. Additionally, by connecting to quantum computers online, visitors can experience a game in multiplayer mode from QPU (Quantum Processing Unit), which utilizes random numbers generated in real time.
The third machine, which served as the basis for the development of the new computer, will also be operated from the Expo site, achieving the maximum entanglement moment of qubits. On August 15th, there will also be a stage event where visitors can access the third machine from their smartphones and create quantum entanglement. In collaboration with Professor Akihiro Kubota at the Department of Information Design, Tama Art University, quantum computer art using actual machines will be displayed, as well as an art project that allows visitors to experience the quantum entanglement on a chip. Entanglement of a large number of qubits requires enhancing the performance of quantum computers. Visitors also can see the process of improvement between April and August at this exhibition.
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Research Background
Quantum computers are expected to quickly solve problems that conventional computers can't solve by using the principles of quantum mechanics. As it has potential to speed up calculations in a variety of areas, including new materials development, finance, drug creation, and machine learning, applications are being actively explored in both domestic and international industrial and academic circles.
In recent years, experiments on quantum computers using superconducting circuits as qubits have progressed. Various companies and organizations, such as Google, IBM, University of Science and Technology of China, Zhejiang University, the American startup Rigetti Computing, and more recently the European startup IQM Quantum Computers, have achieved control of more than 50 qubits.
In Japan, in March 2023, a joint development team of RIKEN, Fujitsu, the University of Osaka, NICT, NTT, and the National Institute of Advanced Industrial Science and Technology (AIST) developed the first superconducting quantum computer produced in Japan, achieving control of more than 50 qubits.
The second machine began operation at Fujitsu in October, and the third machine began operation at the University of Osaka in December. Since then, RIKEN has been developing a 144-qubit machine, and Fujitsu has been developing a 256-qubit machine. Furthermore, a quantum computer manufactured by Fujitsu was delivered to AIST in March of 2025. Thus, scaling up and mass production are steadily progressing at the same time in Japan.
Cloud-based quantum computing is being offered around the world by companies like IBM and Amazon Web Services (AWS), but this requires a variety of software suites. Some parts of RIKEN's first machine, including the dilution refrigerator, were made overseas. Due to their high performance, quantum computers have potential to become a key industry soon, and it has been an ideal form to retain all the domestic technologies within Japan and develop a purely domestic quantum computer with such technologies.
Research Contents
In this research, the research group succeeded in developing a purely domestic superconducting quantum computer system, in which all major parts and software, such as the dilution refrigerator, control device, quantum bit chip, and quantum cloud software, are 100% made in Japan.
The parts used in the first machine such as dilution refrigerator, pulse tube refrigerator, low-noise power supply, cryogenic amplifier, filter, infrared absorber, and magnetic shield, were all made from overseas, but they all were replaced with domestically produced parts in the latest model.
In the superconductive version, the qubits must be cooled to -273.14°C (10mK). First, the entire device is cooled to about 4K by using a pulse tube refrigerator, and then a dilution refrigerator is used to lower the temperature to about -273°C (10mK) by the endothermic effect that occurs when two types of helium with different mass numbers (liquid helium-4 and liquid helium-3) are mixed. ULVAC and ULVAC Cryogenics oversaw the development as part of Moonshot Research and Development Program, Moonshot Goal 6, "Development of Integration Technology for Superconducting Quantum Circuits (Project Manager: Tsuyoshi Yamamoto)," and the completed product was installed at the University of Osaka in March 2025.
Superconducting types can be controlled and observed by using microwaves and a control device is responsible for this transmission and reception. For Moonshot Research and Development Project Moonshot Goal 6, "Development of a Scalable, Highly Integrated Quantum Bit Error Correction System (Project Manager: Kazutoshi Kobayashi)," QuEL, Inc. developed a new control device with higher integration than previous models, which was installed at the University of Osaka in March of the same year. As of July 28, 2025, control devices capable of controlling more than 28 qubits are at the university.
RIKEN is now developing a 144-qubit machine as part of the Ministry of Education, Culture, Sports, Science and Technology's Quantum Leap Flagship Program (MEXT Q-LEAP) "Research and Development of Superconducting Quantum Computers (Representative: Yasunobu Nakamura)," and the same chips for this project are also being provided for this system. As of July 28, 28 of the 144 qubits have been connected to cryogenic wiring. By the end of October, when the Moonshot Research and Development Project ends, the network will be expanded to wiring under 100 qubits, and experiments will be conducted.
A quantum computer does not work with just qubits, control devices, and refrigerators but software development is mandatory. As explaining below, various layers of the system software need to be created, and sustainable development is required. One solution to this is to develop open-source software, which involves a variety of developers. All of the software for this system was developed domestically as open-source software. QURI Parts are used in quantum circuit software, where users input the applications which they want to realize. The software suite that connects the front-end, cloud, and back-end layers uses the Open Quantum Toolchain for Operators and Users (OQTOPUS). Calibration software is required to calibrate microwave intensity and frequency. To correspond to scaling up, QDash runs pulse experiment software to automatically execute the experiments on a large scale. The pulse experiment software is Qubex, which is developed and managed by Akinori Machino, a student (at the time of development) in the Fujii Laboratory of the Graduate School of Engineering Science at the University of Osaka. Further down the layer there is the microwave processing software qubecalib, the control device software quelware, and the FPGA software e7awg_sw, which allow the control device, and ultimately the quantum computer, to operate according to the user's application. The biggest feature of this system is that the entire stack is made up of open-source software, which is unparalleled in the world. It is expected to attract various developers and carry out sustainable development in the future.
As of early July, calibration for eight qubits was conducted, and a demonstration of a two-qubit quantum entangled state was completed. After that, a connection test was done from the cloud, and it was confirmed that the service could be used in the same way as with the third machine. A pre- Expo exhibition and experience session is held on July 28 for quantum researchers and developers in the field.
Fig. 2: List of domestically produced parts for the new quantum computer
Credit: Makoto Negoro
Fig. 3: The software stack of the quantum computer system with open-source software published on GitHub
Credit: Makoto Negoro
Social Impact of the Research
The results of this research proved that Japan possesses all the technologies necessary to build its own quantum computers and can integrate them into a system. The above mentioned other European and American teams that have achieved 50 qubit control are all in the private sector. Meanwhile in Japan, system integration has been achieved in the public sector. The software has been successfully implemented as open source, which is unprecedented in the world. This system is expected to become an open testbed in which various companies can participate for an era in which quantum computers will become a core industry in the future. Quantum computers will contribute to reducing environmental burden through the discovery of new materials and drugs, and optimization, and they will also be useful in everyday life, such as through machine learning.
The following is an explanation of how this system will be used in the near future. To date, QIQB has been using the third machine produced domestically to explore use cases for participants in group work at the Quantum Software Consortium, which includes 40 institutions. It started with small-scale tests using four qubits and the companies whose group work has progressed to actual collaborative research were provided with cloud services. Since installing OQTOPUS on the third machine in April, the number of qubits provided has gradually increased, and as of July 18, a maximum of 42 qubits are provided. It is also being used by staff and students at the University of Osaka for research, with up to 50 qubits operating simultaneously, and experiments are currently underway with a median 1-qubit gate fidelity of 99.9%, and a maximum 2-qubit gate fidelity of 98%, with a median of around 96%.
From May to June, the availability rate was high at 86% for 24 hours/31 days. The second machine has been eagerly waited for maintenance at QIQB. Fig. 4 shows the transition of the number of qubits provided, the degree of coupling between two qubits, and the time of actual machine being used.
This entirely domestically developed system will be connected to the cloud at the special exhibition "entangled moment - [quantum | earth | universe] x art," at Expo 2025 Osaka, Kansai, Japan from August 14 to August 20, where visitors will be able to try it out. The exhibition is set up so that multiple visitors can simultaneously experience the operation of quantum algorithms with up to four qubits. The number of qubits will gradually increase after the exhibition at the Expo is over. The system will also be used by collaborators in Moonshot Research and Development Project Moonshot Goal 6 "Development of Integration Technology for Superconducting Quantum Circuits (Project Manager: Tsuyoshi Yamamoto)," via the cloud. Through this, the research group will promote verification test of quantum error correction.
Fig. 4: Transitions in the number of qubits provided by the third machine, the degree of coupling between two qubits, and the time the machine was used
Credit: Makoto Negoro
