Quantum Universe EXPO

Mikiya Doi, 2nd-year Ph.D. student, Department of Informatics, Graduate School of Information Sciences, Tohoku University

With the goals of promoting the potential of quantum technologies in Italy, especially the possibilities for the social implementation of quantum annealing, and of exploring unprecedented applications of quantum annealing, we planned and organized the QI4U workshop in Rome, Italy. I served as the student leader. In this report, I provide an overview of the event, its activities, and outcomes over the three days. Please excuse my poor writing. I would appreciate it if you read it.

From February 2 to 4, 2026, we held Quantum Infinity for You in Italy: From HPC to Quantum Computing at Sapienza University of Rome (hereafter, the University of Rome). As this was the very first event in the Expo series, we moved forward with planning and preparation largely by trial and error, figuring out what was necessary and what was not. We even encountered the rare event of the University of Rome being affected by cyberattacks targeting the Winter Olympics in Milan. Amid all the chaos, before we knew it, the first day of the event had arrived.

As its name suggests, the University of Rome is a national university located in Rome, the capital of Italy. Its origins date back to 1303, giving it one of the longest histories not only in Italy but also in Europe. The university is home to Professor Giorgio Parisi, who won the Nobel Prize for Physics in 2021, and it is also the former institution of Professor Ohzeki. We are very pleased to have held this workshop in such a meaningful place.

The workshop was attended not only by students from the University of Rome, but also by students from nearby universities. The participants came from a wide range of backgrounds, with physics students forming the core of the group, alongside students from many other disciplines.

On the first day of the event, Professor Federico Ricci-Tersenghi from the University of Rome first introduced our Expo series, followed by a talk on the attractions of combinatorial optimization problems from a physicist's perspective.

Professor Ohzeki then gave a lecture on quantum annealing, focusing on research examples in which it has been applied to social issues. Participants learned about a wide range of topics, including not only distribution and traffic control, but also chemical material discovery, fruit sweetness estimation, and photomosaic art. His declaration that "even theoretical physicists can make money!" likely gave great hope to the physics students in Italy (?).

Our student member, Morita-san, gave a lecture on the principles of simulated annealing and quantum annealing. Aita-san and I explained the formulation of specific combinatorial optimization problems, such as the "number partitioning problem" and the "nurse scheduling problem". Furthermore, Ozaki-san gave a more advanced lecture on black-box optimization using quantum annealing. Sometimes, we delivered the lectures while displaying program code on the screen. During the Q&A sessions following the talks and lectures, many active questions were raised, creating a highly lively atmosphere. At the end of Day 1, we decided on the groups for the group work sessions beginning on Day 2 and wrapped up the first day by discussing what each group would tackle as its assignment.

The second day was entirely group work, with each group consisting of 3–4 participants and one of our student members, brainstorming ideas and developing programs. We had expected that defining the theme and formulating the problem would be difficult. However, every team settled on a theme quickly and moved on to formulating a concrete problem.

For the formulation process, participants probably referred to the lectures from Day 1. They discussed their ideas on the blackboard, going back and forth as they refined their thinking. During the group work, although many participants were meeting for the first time, they expressed their opinions and ideas openly and without hesitation. Watching this from the side, we felt we should learn from this attitude as well. I wonder if Italians go through some special training in discussions.

By the end of Day 2, each team had managed to implement its program to a stage where it looked likely to take shape. Everyone headed home with the feeling that all that remained was the final push toward the final presentations.

On the third day, we spent the morning making the final push to complete the programs, organizing the results, and preparing presentation slides, followed by the final presentation session in the afternoon. Each group divided roles among its members and worked persistently to make it in time for the presentations despite the limited time available.

The themes of the groups were as follows.

• Group 1: School timetable optimization
• Group 2: Portfolio optimization
• Group 3: Optimization of train routing and scheduling in Rome
• Group 4: Optimization of research resource allocation

Each team worked on a theme they felt attached to, whether because they wanted to reduce the burden on people close to them or because it was an issue they had become aware of in their daily lives.

The quality of every team's work was truly impressive. Still, I was especially surprised that one team had even created animations. We had not expected that they would reach this level in just three days (with only about 1.5 days of actual group-work time!).

As mentioned at the beginning, Italy was the first place of this Expo series. The high quality of the final presentations, which were also watched over Zoom by laboratory members responsible for other countries, placed considerable pressure on them.

Finally, after taking a group photo with everyone and then photos within each team, the three-day workshop came to an end.

This event was made possible through the cooperation of many people. First of all, we would like to express our deepest gratitude to Professor Federico Ricci-Tersenghi from the University of Rome. He kindly welcomed the idea of holding this workshop, arranged the venue, and even contributed a great talk. In addition, the members of Professor Ricci-Tersenghi's group provided heartfelt support not only in advertising the workshop but also in helping our student members during our stay.

A total of four student members from Tohoku University and the Institute of Science Tokyo worked on-site to help operate and coordinate this event. I imagine that Morita-san, Aita-san, and Ozaki-san from the Ohzeki Group had to deal with many uncertainties right up until the last moment. I may have caused them inconvenience, but their contributions, each using their own strengths, were an enormous help. And finally, I would like to sincerely thank Professor Ohzeki and Professor Honda for patiently watching over us until the end.