Ippei Danshita from Kindai University and Daichi Kagamihara from Chuo University used Oqtant, a cloud-based service for state-of-the-art physics experiments provided by the company Infleqtion in the USA, to successfully demonstrate the influence of the anomalous tunneling effect on the dynamics of Bose-Einstein condensates (BECs) by operating a BEC experimental setup through the cloud. This is the first time that academic research results obtained using Oqtant have been published as a peer-reviewed scientific paper.
These research findings exemplify the value of a new research approach, in which theoretical physicists conduct experimental studies using cloud-based experimental platforms, and thus hold the potential to significantly expand what theoretical physicists can do in their research. Moreover, the anomalous tunneling is a universal phenomenon predicted to occur not only in BECs but also in materials such as magnets. In this sense, it is of great significance that the influence of such an important phenomenon has been experimentally observed for the first time.
The original paper regarding this work was published in Communications Physics by Nature Portfolio on July 31, 2026.
This work was supported by JST FOREST, JST ASPIRE, KAKENHI, and MEXT Q-LEAP.
1. Key points of this work
- Theoretical physicists have successfully achieved research results by utilizing a cloud service for state-of-the-art physics experiments.
- The anomalous tunneling that this work addressed in BECs of neutral atomic gas is a universal phenomenon predicted to occur also in materials such as magnets, and this work marks the first experimental observation of its influence.
- This work proposes a new research approach for theoretical physicists.
2. Background of this work
In modern physics, researchers are generally divided into two categories: theoretical physicists, who mainly use mathematics to formulate and solve equations to explain physical phenomena, and experimental physicists, who mainly build and operate experimental apparatus for discovering new physical phenomena through experiments. In particular, the level of technical expertise required to conduct state-of-the-art physics experiments is extremely high in general, so it is very difficult for theoretical researchers to build experimental apparatus from scratch on their own and achieve cutting-edge experimental results. Therefore, in order for theoretical physicists to experimentally demonstrate their theoretical predictions, they usually need to find experimentalists who find their theories compelling and who possess both the necessary equipment and expertise for conducting such experimental demonstrations, and secure their cooperation.
However, recent advances in cloud services have offered a solution to this challenge faced by theoretical physicists. There emerge companies that provide cloud services allowing users to freely conduct experiments using state-of-the-art apparatus through the internet. Well-known examples include the quantum computing cloud services provided by IBM and Google. Oqtant, a service provided by the deep-tech company Infleqtion in the USA, is one such cloud service. It allows users to manipulate a gas of atoms, which are trapped in a vacuum chamber using combinations of laser light and magnetic fields, with a separate laser to image the atoms and facilitate analyzing gas dynamics. This atomic gas is cooled down to an extremely low temperature of less than 100 nanokelvin, resulting in a peculiar state of matter known as a Bose-Einstein condensate (BEC), which behaves as a macroscopic quantum matter wave. A theoretical physicist at Kindai University, Ippei Danshita, had been conducting theoretical research on "anomalous tunneling", which is an intriguing phenomenon in BEC, when he was a graduate student. He had strongly hoped that someone would attempt to demonstrate this phenomenon experimentally, but at the time, no experimental researchers stepped forward to conduct such experiments. In 2020, upon learning of Oqtant, Danshita realized that it might enable his group to conduct experiments for addressing the anomalous tunneling, leading to the beginning of this research.
3. Results of this work
A joint research team from Kindai University and Chuo University first carried out theoretical calculations to predict that the oscillatory motion of a BEC in a double-well potential is closely related to the anomalous tunneling. They subsequently used Oqtant to observe the oscillatory motion of the BEC in a double-well potential and measured its period. The experimental results showed good agreement with the theoretical calculations, marking the first experimental observation of the influence of the anomalous tunneling.
These research findings were obtained through a unique methodological approach, in which theoretical physicists conducted experiments remotely using experimental apparatus hosted in the cloud. Moreover, recent theoretical studies have shown that the anomalous tunneling is a universal phenomenon that occurs not only in BECs but also in a wide range of materials, such as magnets. The fact that the first demonstration of such a significant physical phenomenon was made through a cloud service will serve as a powerful catalyst for the migration of other state-of-the-art experimental facilities to the cloud.
4. Published paper
Journal: Communications Physics (2024 Impact factor: 5.8)
Title: Observation of the influence of anomalous tunneling on collective excitations via a cloud experiment platform for Bose-Einstein condensates
Authors: Daichi Kagamihara1,*, Hironori Kazuta2, Yewei Wu3, Noah J. Fitch3, and Ippei Danshita2,*
*Corresponding authors
Affiliations: 1 Department of Physics, Faculty of Fundamental Science and Engineering, Chuo University
2 Physics Course, Department of Science, Kindai University
3 Infleqtion, Inc.
5. Details of the research
Anomalous tunneling refers to a peculiar tunneling property exhibited by sound waves propagating through a BEC. It is well known that the dynamics of microscopic particles such as electrons is subjected to the laws of quantum mechanics. As a result, even if the energy of a particle incident to a barrier is lower than the potential energy of the barrier, it will pass through the barrier with a finite probability, which is a phenomenon known as quantum tunneling. That said, as the energy of the particles decreases, the probability of them passing through (known as the transmission probability) drops rapidly, making it extremely difficult for them to pass through a high barrier. By contrast, as the energy of a BEC sound wave decreases at low energy, its transmission probability increases and approaches unity near zero energy, meaning that the low-energy sound waves exhibit perfect transmission even against a high barrier. Since this behavior is opposite to the tunneling of ordinary quantum particles, it is referred to as the anomalous tunneling. While this anomalous tunneling was first predicted by Russian theoretical physicists as a unique phenomenon exhibited by sound waves of BEC, it has since been theoretically shown that it also occurs in materials such as magnets, suggesting that it is a widespread phenomenon common to materials with certain properties.
We believe that the fact that theoretical physicists were able to experimentally verify such a universal and important physical phenomenon using cloud services in this work is of great significance, as it will have a profound impact on the future direction of physics research.
6. Acknowledgement of research fundings
This work was financially supported by JST FOREST (Grant No. JPMJFR202T), JST ASPIRE (Grant No. JPMJAP24C2), JSPS KAKENHI (Grant No. JP25K17319), and MEXT Q-LEAP (Grant No. JPMXS0118069021).
【Comments by researchers】
Prof. Ippei Danshita
Affiliation: Physics Course, Department of Science, Kindai University
Title: Professor
Comments: Since physics is an empirical science, no matter how theoretically intriguing a proposal may be, it cannot be considered a scientific discovery unless it is verified in experiments. In my career as a theoretical physicist, there are many predictions derived from theoretical research that I personally find fascinating, yet they have not been experimentally verified for some reasons. Thanks to Infleqtion's cloud service Oqtant for state-of-the-art experimental apparatus, we were able to experimentally address one of these intriguing predictions. Going forward, I intend to actively conduct experimental research by utilizing cloud services like Oqtant.
Dr. Daichi Kagamihara
Affiliation: Department of Physics, Faculty of Fundamental Science and Engineering, Chuo University (Former Postdoctoral Researcher, Kindai University)
Title: Assistant Professor
Comments: While I have primarily worked on theoretical research, using a cloud-based experimental platform enabled us to carry out experimental research to verify a theoretically predicted phenomenon. I expect that, as cloud-based experiments in highly controllable systems such as neutral atomic gases become more widely available, it will become possible to flexibly and rapidly test previously unverified theoretical proposals and new theoretical ideas. I look forward to continuing to actively use such emerging research platforms in my future work.
Dr. Noah Fitch
Affiliation: Infleqtion, Inc.
Title: VP of Applied Quantum Sensing
Comments: One of Infleqtion's missions is to expand access to quantum research and technology by delivering enabling hardware, integrated systems, and access to remote platforms. For example, our hardware on the International Space Station allows for remote studies of quantum matter in microgravity, and researchers worldwide can conduct advanced experiments on Infleqtion-hosted systems. This work illustrates what is possible when this access model is implemented terrestrially. Before quantum is everywhere, we can access quantum from anywhere.
