March 23, 2023
Osaka University
Fujitsu Limited
Fujitsu and Osaka University develop new quantum computing architecture,accelerating progress toward practical application of quantum computers
Realizing highly accurate quantum error correction even for quantum computers with about
10,000 physical qubits
News facts:
New quantum computing architecture reduces number of physical qubits (1) requiredfor quantum error correction to 10% of conventional architectures, enabling evenquantum computers in the early FTQC era (2) with a maximum of 10,000 physicalqubits to perform better than classical computers

New architecture represents a significant milestone toward the construction of aquantum computer with 10,000 physical qubits and 64 logical qubits, accelerating
progress toward the realization of genuine fault-tolerant quantum computation (3)Japan, March 23, 2023 – Fujitsu and Osaka University’s Center for Quantum Information
and Quantum Biology (QIQB) today revealed the development of a new, highly efficientanalog rotation quantum computing architecture, representing a significant milestone
toward the realization of practical quantum computing. The new architecture reduces thenumber of physical qubits required for quantum error correction – a prerequisite for therealization of fault-tolerant quantum computing – by 90% from 1 million to 10,000 qubits.
This breakthrough will allow research to embark on the construction of a quantum computerwith 10,000 physical qubits and 64 logical qubits (4), which corresponds to computing
performance of approximately 100,000 times that of the peak performance of conventional
high performance computers.
Moving forward, Fujitsu and Osaka University will further refine this new architecture to leadthe development of quantum computers in the early FTQC era, with the aim of applying
quantum computing applications to a wide range of practical societal issues including
material development and finance.

Error correction for fault-tolerant computing: making practical quantum a reality
Gate-based quantum computers are expected to revolutionize research in a wide range offields including quantum chemistry and complex financial systems, as they will offer
significantly higher calculation performance than current classical computers.
Logical qubits, which consist of multiple physical qubits play a major key role in quantum
error correction technology, and ultimately the realization of practical quantum computersthat can provide fault-tolerant results.
Within conventional quantum computing architectures, calculations are performed using acombination of four error-corrected universal quantum gates (5) (CNOT, H, S, and T gate).
Within these architectures, especially quantum error correction for T-gates requires a large
number of physical qubits, and rotation of the state vector in the quantum calculation
requires repeated logical T-gate operations for approximately fifty times on average. Thus,
the realization of a genuine fault-tolerant quantum computer is estimated to require morethan one million physical qubits in total.
For this reason, quantum computers in the early FTQC era using conventional architecturefor quantum error correction can only conduct calculations on a very limited scale belowthat of classical computers, as they work with a maximum of about 10,000 physical qubits,a number far below that required for genuine, fault-tolerant quantum computing.
To address these issues, Fujitsu and Osaka University developed a new, highly efficientanalog rotation quantum computing architecture that is able to significantly reduce thenumber of physical qubits required for quantum error correction, and enable even quantum
computers with 10,000 physical qubits to perform better than current classical computers,
accelerating progress toward the realization of genuine, fault-tolerant quantum computing.
Fujitsu and Osaka University have been promoting joint R&D in quantum error correction
technology including new quantum computation architectures for the early FTQC era at the“Fujitsu Quantum Computing Joint Research Division,” a collaborative research effort of theQIQB, established on October 1, 2021 at the campus of Osaka University as part of
Fujitsu’s “Fujitsu Small Research Laboratory” program (6).
About the newly developed quantum computing architecture
By redefining the universal quantum gate set, Fujitsu and Osaka University succeeded inimplementing a phase rotating gate – a world first– which enables highly efficient phaserotation, a process which previously required a high number of physical qubits andquantum gate operations.
.
In contrast to conventional architectures that required repeated logical T-gate operations
using a large number of physical qubits, gate operation within the new architecture isperformed by phase rotating directly to any specified angle.
In this way, the two parties succeeded in reducing the number of qubits required forquantum error correction to around 10% of existing technologies, and the number of gate
operations required for arbitrary rotation to approx. 5% of conventional architectures. In
addition, Fujitsu and Osaka University suppressed quantum error probability in physicalqubits to about 13%, thus achieving highly accurate calculations.
The newly developed computing architecture lays the foundation for the construction of aquantum computer with 10,000 physical qubits and 64 logical qubits, which corresponds tocomputing performance of approximately 100,000 times that of the peak performance of
conventional high performance computers.

Figure: Image of the newly developed quantum computing architecture
License：Original content（プレスリリース用に作成されたオリジナルの図）
Usage restriction： No restrictions
Credit：© 2023 Osaka University & Fujitsu Limited
Notes
1.

Physical qubit:
Physical components of quantum computers; smallest unit of quantum information2.

Early FTQC era:
An era where quantum computers work with only a maximum of 10,000 physical qubits
and FTQC is considered to be impossible to realize

3.

Fault-tolerant quantum computation (FTQC):

Fault-tolerant quantum computation achieved through the correction of quantum errors
4.

Logical qubit:
Consisting of multiple physical qubits; smallest logical unit, error-corrected throughredundancy

5.

Universal quantum gate:
A plurality of quantum gates that can perform all quantum calculations by combining
them. Equivalent to AND, XOR, and NOT gates of current computers

6.

Fujitsu Small Research Lab:
Initiative where Fujitsu researchers are embedded at technology incubators atuniversities in Japan and internationally to conduct joint research with some of theleading minds in their fields, including professors as well as the next generation ofresearchers.

Related Links
“Fujitsu and Osaka University Deepen Collaborative Research and Developmentfor Fault-Tolerant Quantum Computers”(press release, October 1, 2021)
https://www.fujitsu.com/global/about/resources/news/press-releases/2021/100101.html

Center for Quantum Information and Quantum Biology (QIQB), Osaka University:
https://qiqb.osaka-u.ac.jp/en/



Fujitsu Quantum:
https://www.fujitsu.com/global/about/research/technology/quantum/

Fujitsu Small Research Lab:https://www.fujitsu.com/global/about/research/srl/

About Osaka UniversityOsaka University was founded in 1931 as one of the seven imperial universities ofJapan and is now one of Japan's leading comprehensive universities with a broad
disciplinary spectrum. This strength is coupled with a singular drive for innovation that
extends throughout the scientific process, from fundamental research to the creation ofapplied technology with positive economic impacts. Its commitment to innovation has
been recognized in Japan and around the world, being named Japan's most innovative
university in 2015 (Reuters 2015 Top 100) and one of the most innovative institutions inthe world in 2017 (Innovative Universities and the Nature Index Innovation 2017). Now,

Osaka University is leveraging its role as a Designated National University Corporation
selected by the Ministry of Education, Culture, Sports, Science and Technology tocontribute to innovation for human welfare, sustainable development of society, andsocial transformation.
Website: https://resou.osaka-u.ac.jp/en
About Fujitsu
Fujitsu’s purpose is to make the world more sustainable by building trust in society throughinnovation. As the digital transformation partner of choice for customers in over 100
countries, our 124,000 employees work to resolve some of the greatest challenges facinghumanity. Our range of services and solutions draw on five key technologies: Computing,Networks, AI, Data & Security, and Converging Technologies, which we bring together todeliver sustainability transformation. Fujitsu Limited (TSE:6702) reported consolidated
revenues of 3.6 trillion yen (US$32 billion) for the fiscal year ended March 31, 2022 andremains the top digital services company in Japan by market share. Find out more:
www.fujitsu.com/

Press Contacts
Masaya Yamamoto
Department of Research Promotion, Office for Center for Quantum Information andQuantum Biology, Osaka University
E-mail:coi-next@qiqb.osaka-u.ac.jp
補足情報

Funding organization(s)☐ Japan Society for the Promotion of Science (JSPS)
 Ministry of Education, Culture, Sports, Science and Technology (MEXT)☐ Japan Agency for Medical Research and Development (AMED) Japan Science and Technology Agency (JST)その他

Quantum Software Research Hub at Osaka University, R&D projectPrimary Keyword: Applied sciences and engineering
Additional Keywords: Computational science, Quantum computing, Qubits, Computerarchitecture