Opening new doors—new results leading to new questions

Denis Arcon 写真

Denis Arčon
Jožef Stefan Institute, Slovenia, Professor

One of the main research topics in my group is magnetism in the presence of “spin frustration.” The target of this visit was the mixed-valence alkali sesquioxide compound Rb4O6. Rb4O6 is a unique system in its family that shows quantum magnetism, however its spin dynamics and other physical properties are not yet well understood. The purpose of the experiment at IMR was to explore the behavior of the spin dynamics of Rb4O6 at low temperatures and high magnetic fields to reveal its overall physical phenomena.

The High Field Laboratory for Superconducting Materials (HFLSM) at IMR is extremely well-known in the world as a facility that has a high level of instrumentations and offers a wide range of magnetic fields at one place. That’s an attractive point, because if it was in other laboratories, we would probably need to go around different facilities to conduct different types of experiments. At IMR, we have measured magnetic phase transition in Rb4O6 under high magnetic field up to 25 T—much higher than what we are able to measure at our home institution. Actually, we had various new results in this visit, but they also opened some new questions. It’s like finding a new door for next stage in the room of “25 T” we entered this time.

I’m also grateful for the GIMRT program, which allowed me to bring my student with me to perform experiments here. Coming to IMR with my student made it possible for us to work in shifts so we can experiment efficiently and maximize our time during our stay. It was also very important for the student to experience and see how the Japanese scientists carry out their research, and create new networks that may lead to more collaboration in the future. We enjoyed our stay at IMR, and we look forward to working together again soon.

GIMRT: Opportunities for optimal experimental conditions and new collaborations

Javier Campo 写真

Javier Campo
University of Zaragoza, Spain, Professor

I experimented at IMR for 10 days in order to conduct a collaborative research with Osaka Prefecture University (OPU). I am collaborating with Prof. Yuko Hosokoshi's group at OPU from long time ago in the study of new magnets done without any metallic ion. Even several years ago, we supervised together a student who obtained a Dual Degree Doctorate. This research is one of the three pillars of my scientific project in Spain, which is the study of magnetic chirality. The other two pillars are the study of new molecular multiferroics compounds and the understanding of the effect of the thermal fluctuations and the stability of magnetic textures (solitons and skyrmions).

I have conducted joint researches with other Japanese universities for a while, but this was my first time experimenting at IMR. As my collaborative researchers said, the unique equipment at IMR provided excellent experimental conditions for us. For example, during the experiment at IMR, we used 20T-SM Magnet with a dilution refrigerator and observed low temperature physics down to 0.1 K in this purely organic magnet synthetized at OPU. In the laboratory at our home institute, we were only able to reach down to 0.3 K, so this experiment will complement the experiment we started back home.

We thank the GIMRT program, and in particular Prof. Hiroyuki Nojiri, for enabling me to bring my student to conduct experiments together. We are very fortunate to have this opportunity to come to Japan for a month, which can be very expensive for our reduced budget. Being able to come with two people instead of one allows us to optimize our time using the wonderful equipment at IMR. The GIMRT also helps to open up opportunities for new collaborations. Through working together for the past couple of weeks and exchanging scientific ideas, Dr. Takumi Kihara became interested in other materials we are familiar in my group. This kind of symbiotic relationship is very precious, and it is an added value to the program.


High-field measurements for next-generation fusion magnets

Zachary Hartwig 写真

Zachary Hartwig
Massachusetts Institute of Technology, Assistant Professor

My research focuses on utilizing high-temperature superconductors (HTS) to advance the performance of high-field, large bore superconducting magnets for fusion applications. Because of the wide variability in HTS obtained from different manufacturers, as well as strong critical current dependence on magnetic field, magnetic field angle, and temperature, it is essential to be able to fully characterize small samples of HTS over the entire potential design space of fusion magnets. This is especially important for the high-field fusion magnets being designed and fabricated at MIT, where peak fields will reach up to 25T. The incredible facilities at Tohoku University IMR, principally the 25T-CSM magnet and HTS critical current characterization system, provide perhaps the only place in the world where HTS samples can be fully characterized to our stringent requirements. Our 2 week measurement campaign on the 25T-CSM was an excellent success, giving us unprecedented HTS data to guide our magnet research and development. This success was primarily due to the expertise and guidance of Professors Satoshi Awaji, Tatsu Okada, and Arnaud Badel from IMR, who were gracious and patient hosts as we ran experiments late into the night for 2 weeks (Thank you!) Our entire team enjoyed our visit very much, particularly the students who helped lead the experiments and were in Japan for the first time. We enjoyed excellent technical discussion over lunch, and dinner, and we are eager to return to continue measurements and pursuing research opportunities with the scientists that we met during our time at IMR.



物質・材料研究機構 グループリーダー 御手洗 容子 写真

物質・材料研究機構 グループリーダー 御手洗 容子




慶應義塾大学理工学部 教授 伊藤 公平 写真

慶應義塾大学理工学部 教授 伊藤 公平





東北大学多元物質科学研究所 教授 蔡 安邦



九州大学大学院理学研究院 教授 巨海 玄道 写真

九州大学大学院理学研究院 教授 巨海 玄道