[No. 158] Hiroko Tokoro

Thank you for this opportunity to contribute to the Keio University alumni "Jukuin Raiou" column. I graduated from the Department of Physics in 1999. After that, I completed my master's program at Kyoto University and my doctoral program at The University of Tokyo. After working as a researcher, a Project Assistant Professor, and an associate professor, I now run my own laboratory at the University of Tsukuba. When I was a student in the Department of Physics, I spent my days busy with things other than studying, like hanging out with friends and working part-time jobs. My grades weren't very good, so the teachers and friends who knew me back then are very surprised that I am now a researcher working at a university. I'm surprised myself. Without thinking too deeply about the future, I simply worked on the interesting things in front of me, which led me to this profession and to continue my research.

I became interested in physics because my high school teacher taught it in a very engaging way. I grew to love physics and decided to major in it at university, choosing the Department of Physics. During my university life up to my third year, which was centered on lectures, I found university-level physics to be quite difficult and spent my time passively attending classes. I remember thinking I was busy every day with things other than lectures, like hanging out with friends and working part-time. Looking back now, I think that was the time in my life when I had the most freedom, but I was completely unaware of it and just spent my days carefree. Not being one to think too deeply about things, I didn't even consider which lab I wanted to join as the time for lab assignments approached. I remember panicking when I saw my friends around me carefully considering their preferred labs. In my panic, I talked to senior students and gathered information about research topics and lab life, and decided to apply for Professor Hideki Miyajima's laboratory. I was interested in the research area of magnetic physics, and to be honest, there was also the (impure) motive of wanting to be in the same lab as a close friend who was also applying.

Upon joining the lab, I first participated in reading groups and seminars, but much of it was specialized and difficult, and I remember thinking how tough it was. Research requires a vast amount of knowledge, and I had to study not only the subjects I liked but also those I was weak in. It was all I could do to keep up with the senior students and my classmates. As I somehow managed to get through each day, my professor eventually gave me a graduation research theme, and my experiments began. In the experiments, I did things like assemble equipment, make the necessary screws myself, and use cryogens like liquid nitrogen and liquid helium. It was all new to me, and everything was interesting and fun. Those were very enjoyable days. Professor Miyajima was always smiling (?) as he taught me various things. I felt that he truly loved and cherished the equipment. Until then, I hadn't had many opportunities to tinker with the inside of equipment, so I thought of it as some kind of difficult, mysterious, yet brilliant box that produced data. But I learned that it was actually made of surprisingly simple parts that I could even assemble and modify myself. As for my graduation research, I had fun up to the point of assembling the equipment, but I struggled to observe the spin-flop phenomenon in magnetic thin films, which was my research theme. I panicked, thinking I wouldn't be able to graduate at this rate, but at the time, I had no problem-solving skills whatsoever. I just remember being completely stuck. In my predicament, I asked for help from senior students and classmates, and with a great deal of generous guidance from Professor Miyajima, I was somehow able to successfully submit my graduation thesis. I still can't forget the sense of accomplishment I felt when I submitted it. Incidentally, I came down with a fever and was sick in bed from the day after I submitted it.

This graduation research experience had a very large impact on my subsequent life. For example, because I was able to learn the fundamentals of equipment, I became skilled at modifying apparatus in my later research, which allowed me to obtain a variety of unique experimental data. It was also extremely meaningful to learn that the most important thing for obtaining good experimental results is preparation. And above all, the friends I made in the Department of Physics are, and always will be, my precious treasures. The time I spent with my friends—eating meals together, having sleepovers, chatting, and studying—are all irreplaceable memories. Even now, my friends and I sometimes get together for a meal. These are the moments when I feel truly glad that I was able to spend my student life in the Department of Physics at Keio University.

Now, as a faculty member, I spend my days in the lab. My specialty is solid-state physics centered on magnetism, the foundations of which I learned in Professor Miyajima's lab. I hope that my students will overcome hardships together with good friends and have a fulfilling research life full of ups and downs. And if possible, I hope they will graduate having experienced firsthand the fun and wonder of equipment and the depth and enjoyment of research, and then go on to make their mark on society.