Quantum Materials Science
Seki Shinichiro Laboratory

Our group develops novel electronic and spintronic functions through the exploration of new materials with nontrivial topology and symmetry.

Usually, the behavior of electrons is controlled by the external electric and magnetic fields. On the other hand, in materials with topologically nontrivial orders, electrons feel giant “emergent” electromagnetic fields due to the curved geometry, and their effective use can dramatically change the way to control electron dynamics.

We design and synthesize new material systems to realize such unique quantum phenomena. By employing the state-of-the-art crystal growth and micro-fabrication techniques, we develop novel electronic functions potentially suitable for various applications such as information processing with ultra-low energy consumption or information detection with ultra-high sensitivity.

In existing magnetic memory devices, information is stored using the “↑” and “↓” spin states in ferromagnets (i.e., “permanent magnets” ), where spins are aligned in parallel. Meanwhile, antiferromagnets, another well-known class of magnetic materials, feature antiparallel spin alignments. The antiferromagnetic spin states “↑↓” and “↓↑” overlap completely upon lattice translation, making it impossible to distinguish between them macroscopically and, as a result, antiferromagnets have long been considered unusable for magnetic information storage

However, recent studies have revealed that when an antiparallel spin arrangement is combined with a specific atomic configuration, the “↑↓” and “↓↑” spin states can be distinguished from one another. This new class of magnetic material is called an “altermagnet” and is attracting significant attention as a promising candidate for next-generation information storage media.

Our laboratory has succeeded in discovering the world’ s first room‑temperature altermagnet that allows information to be both read and written. By advancing the design and functional understanding of this “third magnetic material,” we seek to realize an entirely new paradigm for information processing — one that is ultra‑high‑density, ultra‑low‑power, and ultra‑high‑speed.