Chusei Kiumi

Toward Quantum Advantage: A Quantum–Classical Hybrid Platform for Quantum Simulation

Grant No.：JPMJPR25F1

Researcher : Chusei Kiumi

Outline

By integrating advanced classical hybrid computation techniques, I aim to minimize quantum resources and establish new foundational algorithms for quantum simulation that can be executed on near-future quantum computers. I will systematize an implementation method that optimizes the entire stack from architecture design to hardware realization, and provide a high-performance execution environment as a software library. Building on this development platform, I will present both a theoretical framework and a concrete roadmap for demonstrating practical quantum advantage with minimal quantum resources.

Byunggi Kim

Pioneering quantum transduction via hypersonic phononic nanoresonators

Grant No.：JPMJPR25F2

Researcher : Byunggi Kim

Outline

Hypersonic nanoresonators are expected to serve as bridges connecting quantum electronics and photonics. However, achieving strong coupling among multiple quantum interfaces remains a major challenge, and improving conversion efficiency is a central challenge. In this project, I aim to elucidate the mechanisms of hybrid quantum interfaces that enable strong coupling of electrical, mechanical, and optical degrees of freedom on a piezoelectric platform. Leveraging advanced nanofabrication technologies, I will pursue the realization of high-efficiency coherent quantum transducers.

Shotaro Shirai

Development of a Quantum-to-Digital Interface Using Single-Flux-Quantum Circuits

Grant No.：JPMJPR25F3

Researcher : Shotaro Shirai

Outline

This project aims to develop a scalable superconducting qubit control and readout system that eliminates the need for extensive wiring from room-temperature electronics, a major bottleneck in scaling superconducting quantum computers. Based on knowledge from single flux quantum circuits, which operate with ultra-low power dissipation at cryogenic temperatures, and high-coherence superconducting quantum circuits, I will implement on-chip analog-to-digital conversion devices and establish an essential quantum-to-digital interface technology. This interface is crucial for connecting physical qubits to higher-level layers that implement quantum error correction and logical operations, thereby paving the way for the realization of large-scale superconducting quantum computing systems.

Hideaki Takashima

Developing the fundamental technologies for fault-tolerant photonic quantum systems based on spin control

Grant No.：JPMJPR25F4

Researcher : Hideaki Takashima

Outline

In this study, I aim to realize fault-tolerant photonic quantum technologies by developing novel techniques for generating entangled photons through hybrid systems of photons and spins in solid-state materials. To this end, I will fabricate diamond waveguides that include single defect centers with high photon extraction efficiency and realize spin–photon entanglement at low temperatures. Furthermore, by utilizing this spin-photon entanglement, I will establish entanglement among multiple spins mediated by photons. This approach will open up the foundation for innovative fault-tolerant photonic quantum technologies based on precise spin control.

Lento Nagano

Circuit Design and Performance Evaluation for Large-Scale Digital Quantum Simulations of Lattice Gauge Theories via Quantum-Classical Hybrid Algorithms

Grant No.：JPMJPR25F5

Researcher : Lento Nagano

Outline

In this study, I design quantum circuits for digital quantum simulations of lattice gauge theories and evaluate both computational cost and accuracy. In particular, I investigate errors in two-dimensional non-Abelian gauge theories using quantum-classical hybrid algorithms. Through this analysis, I clarify the computational resources required to approach the continuum limit and pave the way for future simulations of three-dimensional systems.

Koki Nishimura

Quantum sensing via optically detected nuclear magnetic resonance based on molecular engineering

Grant No.：JPMJPR25F6

Researcher : Koki Nishimura

Outline

Quantum nano-sensors based on electron spins are limited by their short relaxation times. In contrast, nuclear spins exhibit drastically longer relaxation times, even within molecules in solution. In this project, I aim to develop a new class of quantum molecular sensors by designing molecules that combine nuclear-spin-selective reactions with optical emission, enabling direct optical readout of nuclear spin states. This approach allows time-series analyses on the millisecond scale, providing an innovative platform for next-generation quantum sensing technologies.

Hideaki Hakoshima

Development of Virtual Operations Toward Practical Implementation of Early Fault-Tolerant Quantum Computers

Grant No.：JPMJPR25F7

Researcher : Hideaki Hakoshima

Outline

Early fault-tolerant quantum computing (early-FTQC), a quantum computer partially incorporating quantum error correction, is attracting significant attention. In this research, I will develop quantum algorithms for early-FTQC by effectively reducing noise effects through the application of operations—including classical processing—referred to as virtual operations.

Sota Yoshida

Quantum Many-Body Systems with Three-Body Interactions

Grant No.：JPMJPR25F8

Researcher : Sota Yoshida

Outline

Nuclear many-body systems, characterized by short-range repulsion, medium-range attraction, and three-body forces, are strongly correlated quantum systems and present formidable challenges for both classical and quantum computation. In this project, I will develop integrated frameworks encompassing ansatz suitable for nuclear many-body states, latent representation of three-body forces, quantum algorithms, and software infrastructure. Through these efforts, I aim to establish novel quantum simulation techniques that explicitly incorporate three-body forces, while providing a distinctive testbed for advancing both quantum software and hardware.

Kouki Yonaga

Developing Fundamental Technologies for Quantum–Digital Integrated Deep Learning

Grant No.：JPMJPR25F9

Researcher : Kouki Yonaga

Outline

This study aims to establish a foundation for quantum–digital integrated deep learning by combining classical digital computing, quantum-inspired machine learning, quantum simulation, and quantum–classical hybrid deep learning. Rather than depending on quantum computers, which are still in the developmental stage, I seek to establish quantum deep learning techniques that can be executed on classical digital computers and to elucidate the impact of quantum effects on learning performance.

Naru Yoneda

Creation of entangled two-photon absorption holographic microscopy

Grant No.：JPMJPR25FA

Researcher : Naru Yoneda

Outline

The two-photon absorption holographic microscope enables the observation and manipulation of neural activity, providing a pathway to elucidate higher brain functions. However, conventional two-photon absorption requires high-power ultrashort-pulse lasers, which cause photobleaching and limit the duration of observation. In this project, I propose the creation of a holographic microscope that integrates entangled two-photon absorption, which efficiently induces fluorescence. This approach enables ultra-low-invasive, long-term observation and manipulation of neural activity, thereby contributing to the advancement of neuroscience.

Bartosz Regula

Elucidating the limits of quantum information processing through information-theoretic and mathematical techniques

Grant No.：JPMJPR25FB

Researcher : Bartosz Regula

Outline

As quantum technologies advance, it becomes crucial to optimize the different ways that quantum phenomena can be used to our advantage, and to characterize the ultimate limits of our ability to exploit quantum resources in practice. This project will develop new theoretical methods for the understanding and benchmarking of the capabilities and limitations of quantum information processing tasks. This will be accomplished by using the underlying information-theoretic structure of quantum information, in particular by advancing the study of information-theoretic techniques and the development of new mathematical methods for the characterization of quantum communication and more general quantum information processing protocols.