ICEPP-QUP Quantum Workshop 2026

18 May 2026, 10:00 → 19 May 2026, 18:00 Asia/Tokyo

Koshiba Hall, The University of Tokyo

Koji Terashi (University of Tokyo (JP)), Masaya Ishino (University of Tokyo (JP)), Tatsumi Nitta (KEK), Toshiyuki Azuma (KEK)

Short URL: https://indico.global/e/IQWS2026

Over the past decade, quantum technologies have progressed at an extraordinary pace. Advances in quantum computing and quantum sensing, together with the development of fundamental quantum algorithms and a growing range of quantum applications, have brought the realization of quantum advantage increasingly close.

Building on this momentum, this workshop aims to provide a forum for discussing the current state and future directions of quantum technologies. The workshop is organized around quantum theory, quantum computation, and quantum sensing as central themes, while exploring their experimental and theoretical applications across diverse areas such as particle physics, cosmology, and nuclear physics.

By bringing together researchers from different communities and highlighting forward-looking ideas as well as state-of-the-art quantum technologies and computational techniques, the workshop seeks to foster discussions on new opportunities, including novel quantum error-correction strategies, applications to fault-tolerant quantum computing, and advanced quantum sensing enabled by cutting-edge quantum algorithms.

Invited Speakers :

• Yutaro Iiyama (ICEPP, UTokyo)
• Yoshiro Takahashi (Kyoto U.)
• Takaaki Takenaka (NTT)
• Shion Chen (Kyoto U.)
• Tatsumi Nitta (KEK QUP)
• Atsushi Noguchi (UTokyo)
• Keisuke Fujii (Kyoto U.)
• Masazumi Honda (RIKEN)
• Seiji Yunoki (RIKEN)
• Nobuyuki Yoshioka (ICEPP, UTokyo)

(Japanese alphabetical order)

 Those who want to present talk or poster are asked to submit via the “Call for Abstracts” page (submission is closed).

Participation registration is open now. The registration is closed.

Note: We plan to organize this workshop in a "mixed" language mode, i.e, the presentation slides will be prepared in English, while the oral talk and discussion will be given in Japanese.

Lunch Map.pdf

Monday 18 May

10:00 → 12:30 Session 1

Convener: Koji Terashi (University of Tokyo (JP))

10:00 Introduction

Speaker: Toshiyuki Azuma (KEK)

10:05 New physics search using ultracold atoms

In this talk, I will report our recent experiments of precision measurement for new physics beyond the Standard Model. Owing to the existence of ultranarrow optical transitions between the ground and metastable states and many isotopes we search for a new hypothetical particle mediating a force between an electron and a neutron, through precision isotope-shift measurements using ultracold bosonic Yb atoms in a magic-wavelength lattice. Implications of the results on some specific models of elementary particle theory as well as nuclear physics are also mentioned. In addition, we only briefly report on our progress towards quantum computing using Yb atom tweezer array.

Speaker: Yoshiro Takahashi (Kyoto University)

ICCEP_QUP_Yoshiro_Takahashi.pdf

10:50 Dark Matter Search with a Superconducting Quantum Processor

A system of transmon qubits is proposed as a potential platform to detect dark matter (DM) [1]. The sensitivity of the detector was shown to be enhanced by entangling a large number of qubits under the assumption that the hidden photon associated with the DM acts equally on all qubits as the same unitary operator $U_\mathrm{DM}$. We call this signal collective noise.

Qubits can be protected from collective noise by the so-called noiseless subsystem [2]. Consider a system of 3 qubits. Using the permutation symmetry of collective noise, it can be shown that there is a unitary transformation $U_E \in U(2^3)$, such that [2]
$$ U_E^\dagger (U_\mathrm{DM}^{\otimes 3})U_E|0\rangle |\phi\rangle| \psi\rangle = |0\rangle |\phi\rangle U_\mathrm{DM}|\psi\rangle. $$ $|\phi\rangle$ is immune to noise under this error-avoiding encoding. We take $|\phi\rangle=|0\rangle$ and $|\psi \rangle \in {|0\rangle, |+\rangle, |y+\rangle}$ in the following. [1] showed that the sensitivity of the proposed detector is $\propto n_q^2 \delta^2$, where $n_q$ is the number of qubits that participate in the entanglement and $\delta=\eta \tau$ is a small parameter where $\eta$ is a coupling parameter between hidden photon DM and transmons and $\tau$ is the integration time in detector. In this new proposal, deviation of the measurement outcome from the no-noise case is proportional to $\sin \delta\sim \delta$, although the sensitivity enhancement factor may not be literally $\sim 1/\delta$ if the standard quantum limit is taken into account, for example. The output state $|00\rangle$ of the first two qubits signals that the noise is collective. In our talk, we will introduce the quantum circuit implementing $U_E$ and propose a QPU design that can be fabricated within near-future technology. $[1]$ Chen, Shion and Fukuda, Hajime and Inada, Toshiaki and Moroi, Takeo and Nitta, Tatsumi and Sichanugrist, Thanaporn, Phys. Rev. D **110**, 115021 (2024) $[2]$ G\"ung\"ord\"u, Utkan and Li, Chi-Kwong and Nakahara, Mikio and Poon, Yiu-Tung and Sze, Nung-Sing, Phys. Rev. A 89, 042301 (2014)

Speaker: Mikio Nakahara (IQM Quantum Computers)

11:15 Break

11:45 Toward Practical Quantum Advantage on Early Fault-Tolerant Quantum Computers

We present a perspective on achieving practical quantum advantage in the era of early fault-tolerant quantum computers (early FTQC). We begin with a brief overview of recent progress in quantum error correction, which has demonstrated initial error suppression but remains far from large-scale fault tolerance, and then identify the central bottlenecks for early FTQC, including the substantial space–time overhead of error correction, the cost of non-Clifford operations, and limitations in decoding and control. To address these challenges, we introduce our group’s recent advances in architecture, compilation, and error correction, including methods for reducing T-count, enabling efficient logical analog rotations, and developing scalable low-overhead decoding strategies. Finally, we present resource estimates for scientifically and industrially relevant applications, highlighting regimes in which early FTQC devices with realistic physical error rates and qubit counts may achieve meaningful computational advantage.

Speaker: Keisuke Fujii (Kyoto University)

earlyFTQC.pdf

12:30 → 12:40 写真撮影（理学部1号館の1階ピロティ）

12:40 → 14:00 Lunch

14:00 → 16:25 Session 2

Convener: Ryu Sawada (University of Tokyo (JP))

14:00 Exploring Many-Body Physics with Quantum Computers: Quantum Dynamics and Quantum-HPC Hybrid Computation

Quantum computers are opening new opportunities for exploring quantum many-body systems, both as programmable platforms for studying nonequilibrium dynamics and as computational tools within hybrid quantum-classical workflows. In this talk, I will present recent progress in these two directions, focusing first on quantum dynamics experiments on digital quantum processors [1-4] and then on hybrid quantum-HPC computation for many-body physics and chemistry [5-7].

I will begin with recent experiments on nonequilibrium quantum dynamics in programmable superconducting-qubit systems, including Floquet many-body dynamics in regimes that are difficult to access with classical simulations alone. These studies demonstrate that present-day quantum processors can already serve as valuable experimental platforms for exploring complex many-body phenomena, especially when combined with classical verification methods such as tensor-network simulations.

I will then discuss quantum-classical hybrid computation that integrate quantum hardware with high-performance classical computing to address problems beyond the reach of conventional exact diagonalization. Representative examples include selected configuration interaction approaches for ground-state calculations, as well as quantum-enhanced tensor-network approaches. Enabled by close integration between on-premise quantum processors and large-scale supercomputers such as Fugaku, these approaches illustrate how hybrid architectures can extend the frontier of practically tractable computation.

These developments point to a new regime of quantum computational science, in which quantum processors play a dual role: as experimental platforms for probing quantum many-body dynamics and as accelerators within hybrid computational workflows. This combined perspective offers a practical route toward scientifically meaningful quantum advantage before the advent of fully fault-tolerant quantum computing

[1] K. Shinjo, K. Seki, T. Shirakawa, R.-Y. Sun, and S. Yunoki, “Unveiling clean two-dimensional discrete time crystals on a digital quantum computer”, arXiv:2403.16718.
[2] K. Shinjo, K. Seki, and S. Yunoki, “Noise-stabilized discrete time crystals on digital quantum processors”, arXiv:2510.13577.
[3] K. Shinjo, K. Seki, and S. Yunoki, “Quantum synchronization and chimera states in a programable quantum many-body system”, arXiv:2603.11910.
[4] K. Nagao, T. Shirakawa, R.-Y. Sun, P. Prelovsek, and S. Yunoki, “Probing many-body localization crossover in quasiperiodic Floquet circuits on a quantum processor”, arXiv:2603.12675.
[5] J. Robledo-Moreno et al., “Chemistry beyond the scale of exact diagonalization on a quantum-centric supercomputer”, Science Advances 11, eadu9991 (2025).
[6] T. Shirakawa et al., “Closed-loop calculations of electronic structure on a quantum processor and a classical supercomputer at full scale”, arXiv:2511.00224.
[7] P. Yoo ei al., “Extending the handover-iterative VQE to challenging strongly correlated systems: N2 and Fe-S cluster”, arXiv:2601.08137.

Speaker: Seiji Yunoki (RIKEN)

14:45 A challenge for quantum few-body problems using machine learning with quantum annealing machine

Quantum annealing machines are attracting attention as a new type of quantum computer in addition to conventional gate-based quantum computers. They have been introduced to the market by D-Wave company and can also be used on the cloud. Many companies are also considering using and operating them in the future, and it is expected that they will also be practically used more widely in the scientific field.
Accurate computtatinal reproduction of quantum few-body systems such as hadrons,nuclei, atoms, etc have been a central interest in science　because it is fundamental research into understanding quantum systems.
In this talk, I will explain how quantum machine learning can be implemented using a quantum annealing machine to perform calculations on quantum few-body systems, and provide actual calculation examples.

Speaker: Shigeyoshi Aoyama (KEK CRC)

15:10 Break

15:40 Fault-tolerant quantum algorithms for many-body systems

Quantum computers are expected to accelerate various tasks including quantum simulation and sensing, which are holistically referred to as quantum advantage. In this talk, we review the current state-of-the-art in fault-tolerant quantum algorithms, such as the quantum signal processing in the context of state preparation and Hamiltonian simulation, and dissipative quantum simulation for finite-temperature states. Furthermore, we envision the timeline for its realization in hardwares.

Speaker: Nobuyuki Yoshioka (ICEPP, The University of Tokyo)

16:25 → 17:45 Poster Session

16:25 Simulating the Physics of Topological Defects in the Early Universe: From Cosmological Phase Transitions to Baryon-Number-Violating Processes

Cosmological phase transitions in the early universe can generate topological defects through the Kibble–Zurek mechanism. These defects are not only a generic consequence of nonequilibrium symmetry-breaking dynamics, but may also have profound implications for particle physics and cosmology. In particular, topological defects formed during a grand unified symmetry-breaking transition may catalyze baryon-number-violating processes, such as proton decay, through the Callan–Rubakov effect. This project aims to simulate the formation and dynamics of such defects and to investigate how defect-mediated processes may provide insight into unresolved mysteries of the early universe. By using modern simulation platforms, including quantum computing, this work seeks to open a new route to studying the physics of topological defects in the early universe that is otherwise difficult to access experimentally.

Speaker: Fumika Suzuki

16:30 Search for Hidden Photon Dark Matter Using Direct Excitation of Superconducting Qubits

We present a search for hidden photon dark matter using superconducting qubits, based on the method proposed by our group (Moroi et al., Phys. Rev. Lett. 131, 211001 (2023)). Hidden photon dark matter induces an AC electric field through the kinetic mixing with ordinary photons. This electric field can excite a qubit on resonance. Assuming that fake excitations are uniformly distributed in the frequency domain, a narrow dark matter signal can be detected by sweeping the frequency of tunable qubits. To determine the excitation rate at each frequency, we repeatedly let the qubit idle for a fixed time and measure its state. In this poster, we show the latest results of hidden photon searches by this detection method

Speaker: KARIN WATANABE (The University of Tokyo)

16:35 A Conceptual Quantum Architecture for Enhancing Urgent Volcanic Hazard Forecasting

Urgent computing for disaster response currently faces severe computational bottlenecks. In the context of active volcanology, providing early warning capabilities and rapid impact forecasts for a wide spectrum of volcanic hazards—including those from explosive eruptions—requires complex numerical simulations and the real-time measurement, analysis, and assimilation of satellite and field data.
Currently, classical automated hazard assessment workflows demand extensive high-performance computing (HPC) resources that often fail to deliver adequate processing speeds during real-time emergencies. To address these challenges, this work investigates the integration of emerging quantum technologies into time-critical geoscience applications. Specifically, we propose a conceptual framework for a Hybrid Quantum-Classical Volcanic Hazard Assessment Workflow that leverages two distinct quantum advancements. First, we explore the incorporation of quantum-enhanced data acquisition, such as high-precision quantum sensors, to significantly improve the resolution and accuracy of initial observations. Second, we examine the application of quantum algorithms to data assimilation and probabilistic modeling. By doing so, we aim to reduce latency and enhance forecast reliability through superior optimization and sampling techniques. This poster outlines the theoretical architecture of the workflow, presents a roadmap for benchmarking performance, and seeks to foster interdisciplinary discussion to identify collaborative pathways for quantum algorithm development in the geosciences.

Speaker: Dr Beatriz Martinez Montesinos (Istituto Nazionale di Geofisica e Vulcanologia (INGV))

MartinezMontesinos_Massaro.pdf

16:40 Dynamics of entanglement asymmetry for space-inversion symmetry of free fermions on honeycomb lattices

The dynamics of isolated quantum many-body systems and the resulting relaxation of subsystems constitute one of the central problems in the study of quantum many-body physics. In particular, recent studies have attempted to understand subsystem relaxation from the viewpoint of symmetry restoration. However, the influence of band structure and geometric properties of a system on symmetry restoration remains an open question.

In this study, we investigate how space-inversion symmetry is restored in the dynamics of free fermions on a honeycomb lattice by using the entanglement asymmetry (EA), which provides a quantitative measure of symmetry breaking. Specifically, we prepare as an initial state the ground state with broken inversion symmetry by introducing an energy offset $M$($\neq$ 0) between the two sublattices, and compute the time evolution of EA after a quantum quench to $M=0$.

We find that, although the post-quench Hamiltonian is inversion symmetric, the symmetry is not restored at the subsystem level. We further show that the condition for the absence of symmetry restoration is determined by the geometric properties of the subsystem. Moreover, using a semiclassical effective theory, we demonstrate that this phenomenon originates from quasiparticles associated with a flat band.

Speaker: Ryogo Hara (The university of Electro-Communications)

16:45 Analytical solution of the Schrödinger equation with 1/r^3 and attractive 1/r^2 potentials: Universal three-body parameter of mixed-dimensional Efimov states

We study the Schrödinger equation with $1/r^3$ and attractive $1/r^2$ potentials. Using the quantum defect theory, we obtain analytical solutions for both repulsive and attractive $1/r^3$ interactions. The obtained discrete-scale-invariant energies and wave functions, validated by excellent agreement with numerical results, provide a natural framework for describing the universality of Efimov states in mixed dimension. Specifically, we consider a three-body system consisting of two heavy particles with large dipole moments confined to a quasi-one-dimensional geometry and resonantly interacting with an unconfined light particle. With the Born–Oppenheimer approximation, this system is effectively reduced to the Schrödinger equation with $1/r^3$ and $1/r^2$ potentials, and manifests the Efimov effect. Our analytical solution suggests that, for repulsive dipole interactions, the three-body parameter of the mixed-dimensional Efimov states is universally set by the dipolar length scale, whereas for attractive interactions it explicitly depends on the short-range phase. We also investigate the effects of finite transverse confinement and find that our analytical results are useful for describing the Efimov states composed of two polar molecules and a light atom.

Speaker: Yuki Ohishi (Department of Engineering Science, University of Electro-Communications)

16:50 Error-Mitigated Quantum Simulation of Lattice Gauge Theory

I present the results of simulations of lattice gauge theory (LGT) based on the loop-string-hadron formulation, performed on a Quantinuum ion-trap quantum computer. I tested two error mitigation methods—one based on a depolarizing noise model and another using error detection via post-selection based on Gauss’s law—and found that both worked well.

Speaker: Toshiaki Kaji (University of Tokyo (JP))

16:55 Effects of complex interaction between polarons and localization phenomena

Recently, quantum simulation with ultracold atoms has become a powerful tool for exploring many-body physics. In particular, impurity atoms immersed in quantum media such as degenerate Fermi gases and Bose–Einstein condensates, lead to the formation of Fermi and Bose polarons. Beyond single-polaron properties, polaron-polaron interactions have been actively investigated and experimentally observed in both ultracold atom systems and semiconductors. Recent theoretical studies have further shown that the two polarons interact not only via real-valued potentials, but also acquire imaginary components originating from the open-quantum-system nature of the impurity-medium coupling. In this work, we investigate the effects of complex interactions between two polarons and demonstrate that the complex potential leads to the emergence of localized states and exceptional points, characteristic of non-Hermitian physics. Furthermore, we obtain analytical solutions that describe both localized and delocalized states, providing new insights into non-Hermitian physics in quantum impurity systems.

Speaker: Kyoka Tsunoda (Department of Engineering Science, University of Electro-Communications)

17:00 A Novel Photolithography-only Fabrication Method of Manhattan Josephson Junctions for Transmon Qubits

We report a novel fabrication method for transmon qubits, which are fundamental devices in superconducting quantum computers and circuit quantum electrodynamics. Our approach eliminates the need for time- and cost-intensive electron-beam lithography by employing only photolithography combined with angled deposition. Using this method, we successfully realize Josephson junctions with areas comparable to those fabricated by conventional techniques, and evaluate their performance at low temperatures. The proposed fabrication scheme is expected to be advantageous for quantum electronics in terms of process reproducibility and scalability for large-scale circuit integration.

Speaker: Koki Aoyanagi (Kyoto University)

17:05 Recent progress in the development of a galvanically contacted cavity-qubit hybrid system for dark matter search

Using superconducting qubits for dark matter detection has been drawing a lot of attention recently. Since some ultra-light dark matter, such as axions and dark photons, is theoretically predicted to convert to ordinary photons whose frequency is around GHz, weak photon sensing techniques with qubits can be used. Besides, such dark matter sensing is performed in a dilution refrigerator to avoid thermal noise, for the same reason in quantum technology. For example, superconducting qubits are used as sensors themselves [1,2,3], or cavity frequency tuners [4,5].

In terms of using a cavity-qubit hybrid system, stronger coupling between them is one of the efficient ways to utilize cavity-qubit interaction. In this poster, I would like to introduce a galvanically contacted cavity-qubit hybrid system. Contacting the wall of three-dimensional cavity and the pads of superconducting qubits with indium bumping, realizes the strongest coupling which couldn’t be realized with capacitive coupling.

In this poster session, I will talk about the simulations of this hybrid system, the implementation status, and future prospects for dark matter sensing.

[1] A. V. Dixit, et al., Phys. Rev. Lett. 126, 141302 (2021).
[2] S. Chen, et al., Phys. Rev. Lett. 131, 211001 (2023).
[3] C. Braggio, et al., Phys. Rev. X 15, 021031 (2025).
[4] F. Zhao, et al., Phys. Rev. Lett. 135, 201002 (2025).
[5] K. Nakazono et al., arXiv:2505.15619 (2025).

Speaker: Kan Nakazono (the University of Tokyo)

17:10 Nuclear Laser Spectroscopy of Thorium-229 toward the Development of a Nuclear Clock

The 8.4 eV isomeric state of Thorium-229 (²²⁹Th) is the only known nuclear excited state in the laser-accessible energy range and is therefore a promising candidate for a nuclear clock based on this nuclear resonance frequency. In recent years, several research groups, including ours, have reported successful laser excitation of this transition, further demonstrating the feasibility of this approach.
Toward direct laser excitation of the ²²⁹Th nuclear transition, we have been developing a vacuum-ultraviolet (VUV) laser system. Using this VUV laser system, we performed nuclear laser spectroscopy of ²²⁹Th-doped CaF₂ crystals. We resolved the crystal-field splitting of the nuclear resonance with a high signal-to-background ratio.
In this presentation, we report recent spectroscopic results and discuss current progress toward future laser spectroscopy of ²²⁹Th trapped ions.

Speaker: Sayuri Takatori (Okayama university)

17:15 Coherent Channel Estimation with Qumulant Expansion

量子チャネル推定（量子プロセストモグラフィ）では、必要な測定数がシステムサイズに対して指数関数的に増大しうる点が大きな課題である。これに対し、実機量子デバイスにおけるノイズが局所的に生じやすいという性質を利用し、局所測定から全体系のチャネルを近似的に再構成するアプローチが有望である。本研究では、キュムラント展開を量子プロセストモグラフィに応用することでノイズの局所性を体系的に取り込み、全体系のプロセスを再構成する手法を提案する。さらにコヒーレントチャネルを対象に、限られた局所情報からでも高精度推定が可能となる条件を解析的に導出した。加えて、提案手法に基づく低次のRDMトモグラフィと高次のRDMトモグラフィの間でサンプル複雑性を比較し、同等の推定精度を達成するための測定資源が大幅に削減され得ることを示した。

Speaker: Shu Komada (University of Tokyo (JP))

17:20 Development of a Single Microwave Photon Detector Using a Superconducting Qubit for Axion Searches

Axions are a promising dark matter candidate, but the microwave signals expected from axion-photon conversion are extremely weak. To overcome the limitations of the standard quantum limit (SQL), single microwave photon detectors provide a promising approach for axion searches. We are developing a single microwave photon detector based on a superconducting transmon qubit for the detection of such weak microwave photons. This study aims to establish a highly sensitive quantum sensor and contribute to future quantum-enhanced searches for axion dark matter.

Speaker: Chikara Kawai (The University of Tokyo)

17:25 The status of preparation of the solar axion search using TES with 57Fe target at QUP

At QUP, we are developing an experiment to search for the solar axion. The axion is a hypothetical particle which is introduced as a solution for the strong-CP problem and is a candidate for cosmological dark matter, This experiment aims to detect axions from the Sun. Especially 14.4keV monochromatic axion from the reaction with $^{57}\rm{Fe}$ nuclei.
Our detector has the same atom plated on Si wafer, and the transition edge sensor can detect axion energy with excellent energy resolution and efficiency. We adopt micro-wave multiplexing technology to readout multiple sensors with one cable for the purpose of reduction of thermal inlet. In the poster, the design, and the status of the integration of the experimental system will be presented.

Speaker: Daisuke Kaneko (High Energy Accelerator Research Organization)

18:00 → 20:00 Reception

Tuesday 19 May

09:30 → 13:25 Session 3

Convener: Toshiaki Inada (ICEPP, The University of Tokyo)

09:30 Superconducting qubits and cavities for DM sensors at QUP-KEK

As governments and major technology companies lead development on quantum computers, underlying quantum technologies have undergone revolutionary advances. While many of these technologies are, in principle, applicable to particle physics experiments, applications remain limited so far.
In this talk, we will introduce the dark matter search program based on superconducting qubits conducted by KEK/QUP as an example, I will provide an overview of the new possibilities for particle physics experiments enabled by state-of-the-art quantum technologies.

Speaker: Tatsumi Nitta (KEK-QUP)

ICEPP-QUPws2026_nitta_260519.pdf

10:15 High-Q Three-Dimensional Superconducting Cavities: Development and Applications for Quantum Technologies

Quantum technologies based on superconducting circuits have advanced rapidly in recent years. Recent progress has increasingly underscored the importance of materials and microscopic loss mechanisms, particularly dielectric loss and two-level-system physics, as planar superconducting qubits enter the millisecond regime. Advances in these directions have also driven further improvements in high-Q three-dimensional superconducting cavities for quantum applications. Their exceptional quality factors and low loss enable applications such as the characterization of interface dielectric loss, long-lived quantum memories, and searches for dark photon dark matter.
In this talk, I will present our efforts to improve the quality factor of three-dimensional superconducting cavities and discuss experiments on bosonic quantum error correction in a cavity-transmon architecture, where logical information is encoded in cavity Fock states and their superpositions.

Speaker: Takaaki Takenaka (NTT)

11:00 Break

11:30 TBD

Speaker: Atsushi Noguchi (The University of Tokyo)

12:15 Searches for New Physics Using Ytterbium

Extremely high precision measurement of frequency ratio and difference realized by optical atomic clocks enables us to perform not only accurate time-keeping but also searches for new physics. One of the earliest works on this is the search for time variation of fundamental constants, such as the proton-to-electron mass ratio and the fine structure constant. Recent trend is to precisely measure isotope shifts to investigate new force between an electron and a neutron. Ytterbium is one of the most popular atoms for these purposes. Initially, transitions in Yb⁺ ions were utilized. Recently, the new clock transition at 431 nm with an f electron excited is expected to serve as an important role in these topics.

In this talk, I first describe a brief overview of the topic. I then discuss my recent work on the 431 nm transition and a search for the new force between an electron and a neutron. Finally, I will describe the future direction of the research including the search for time variation of fundamental constants in my group.

Speaker: Akio Kawasaki (NMIJ/AIST)

20260519QUP-ICEPP_share.pdf

12:40 → 14:10 Lunch

14:10 → 17:30 Session 4

Convener: Tatsumi Nitta (KEK-QUP)

14:10 DarQ experiment - Dark matter searches using spontaneous/controlled superconducting qubit excitations

Superconducting qubits are sensitive to noise - from electromagnetic disturbances, impurities in the material, and even cosmic rays can easily perturb their quantum states and induce errors. From the quantum computer point of view, none of these are desirable. On the other hand, this very sensitivity implies that qubits can be used as highly sensitive sensors for weak fields—such as dark matter. DarQ experiment (Dark matter search using Qubits) is a research effort to search for wave-like dark matter using superconducting qubits.
In this talk, the concept, status, and prospects of the experiment are discussed, as well as the possibility of using quantum computers themselves as dark matter detectors.

Speaker: Shion Chen (Grad. School of Sci., Kyoto University)

ICEPPQUP_20260519.pdf

14:55 A Multi-Front Approach to Advancing High-Energy Physics with Quantum Technologies

High-energy physics (HEP) demands not only experimental probes of known and unknown particles but also an intricate understanding of the theory of gauge fields. At ICEPP, we combine our traditional competency in experimental HEP with a rapidly developing expertise in quantum technologies, both theoretical and experimental, developing multiple research thrusts that cover a wide range of topics from table-top blackholes to real-time simulations of nonabelian lattice gauge theories. This presentation will showcase current activities and longer-term strategies of the lab.

Speaker: Yutaro Iiyama (University of Tokyo (JP))

15:40 Break

16:10 Quantum Error Correction and Lattice gauge theory

We explore relations between quantum error correction and gauge theory. They have a conceptual similarity that quantum error correction provides a redundant description of logical qubits in terms of encoded qubits while gauge theory has a redundancy to describe physical states. Motivated by the conceptual similarity and recent demand for efficient ways to put gauge theories on quantum computers, we develop a comprehensive framework for constructing quantum error correcting codes from Abelian lattice gauge theories using quantum reference frames as a unifying formalism. This talk is mainly based on a joint work with Javier P. Lacambra, Aidan Chatwin-Davies and Philipp A. Hoehn (arXiv:2604.06087).

Speaker: Masazumi Honda (RIKEN)

16:55 A Quantum Algorithm for Measuring Entanglement Asymmetry and Quantum Mpemba Effect

We propose a quantum algorithm to efficiently estimate the entanglement asymmetry, a recently introduced measure of symmetry breaking at the subsystem level that plays a key role in the quantum Mpemba effect. Our protocol combines the SWAP test with ideas from quantum phase estimation and requires a number of measurements independent of the system size, making it suitable for large quantum many-body systems and quantum field theories. As an application, we study the lattice Schwinger model with a θ term and demonstrate that our approach enables the investigation of the quantum Mpemba effect in a quantum field theory setting. We further provide resource estimates for quantum computing implementations.

Speaker: Harunobu Fujimura (大阪大学)

ICEPP-QUP_fujimura.pdf

17:20 Summary/Concluding Remarks

Speaker: Masaya Ishino (University of Tokyo (JP))

Give us your Feedback, Please!

Ishino_summary.pdf