ICEPP-QUP Quantum Workshop 2026

Session

Poster Session

18 May 2026, 16:25

Koshiba Hall, The University of Tokyo

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

Fumika Suzuki

18/05/2026, 16:25

Poster

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...

7. Search for Hidden Photon Dark Matter Using Direct Excitation of Superconducting Qubits

KARIN WATANABE (The University of Tokyo)

18/05/2026, 16:30

Poster

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...

10. A Conceptual Quantum Architecture for Enhancing Urgent Volcanic Hazard Forecasting

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

18/05/2026, 16:35

Poster

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...

11. Dynamics of entanglement asymmetry for space-inversion symmetry of free fermions on honeycomb lattices

Ryogo Hara (The university of Electro-Communications)

18/05/2026, 16:40

Poster

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...

12. 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

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

18/05/2026, 16:45

Poster

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...

14. Error-Mitigated Quantum Simulation of Lattice Gauge Theory

Toshiaki Kaji (University of Tokyo (JP))

18/05/2026, 16:50

Poster

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.

15. Effects of complex interaction between polarons and localization phenomena

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

18/05/2026, 16:55

Poster

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...

33. A Novel Photolithography-only Fabrication Method of Manhattan Josephson Junctions for Transmon Qubits

Koki Aoyanagi (Kyoto University)

18/05/2026, 17:00

Poster

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...

34. Recent progress in the development of a galvanically contacted cavity-qubit hybrid system for dark matter search

Kan Nakazono (the University of Tokyo)

18/05/2026, 17:05

Poster

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...

35. Nuclear Laser Spectroscopy of Thorium-229 toward the Development of a Nuclear Clock

Sayuri Takatori (Okayama university)

18/05/2026, 17:10

Poster

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...

36. Coherent Channel Estimation with Qumulant Expansion

Shu Komada (University of Tokyo (JP))

18/05/2026, 17:15

Poster

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。

38. Development of a Single Microwave Photon Detector Using a Superconducting Qubit for Axion Searches

Chikara Kawai (The University of Tokyo)

18/05/2026, 17:20

Poster

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...

39. The status of preparation of the solar axion search using TES with 57Fe target at QUP

Daisuke Kaneko (High Energy Accelerator Research Organization)

18/05/2026, 17:25

Poster

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...