activity
20242026
collaborators

5 papers

cond-mat.mes-hall2026

Weaving Hopfions from Emergent Monopoles in a Chiral Magnet

Shoya Kasai, Kotaro Shimizu, Shun Okumura +1

Recent advances in three-dimensional magnetization imaging techniques have opened new avenues for exploring topological spin textures beyond domain walls and skyrmions. Among them,…

cond-mat.str-el2026

Creating and Driving a Twist Soliton on a Magnetic Skyrmion Tube

Shoya Kasai, Kotaro Shimizu, Shun Okumura +1

A magnetic skyrmion tube is a three-dimensional topological soliton formed by stacking two-dimensional skyrmions along the out-of-plane direction. Recent real-space observations of…

cond-mat.mes-hall2025

Nonequilibrium dynamics of magnetic hopfions driven by spin-orbit torque

Shoya Kasai, Shun Okumura, Yukitoshi Motome

Hopfions--three-dimensional topological solitons with knotted spin texture--have recently garnered attention in topological magnetism due to their unique topology characterized by…

cond-mat.mes-hall2025

Controlling Knot Topology in Magnetic Hopfions via Spin-orbit Torque

Shoya Kasai, Shun Okumura, Yukitoshi Motome

Knots, characterized by topological invariants called the Hopf number , arise from the intertwining of strings and exhibit diverse configurations. The knot structures have recen…

cond-mat.str-el2024

Three-dimensional Topological Superstructure of Magnetic Hopfions Threaded by Meron Strings in Easy-plane Magnets

Shoya Kasai, Kotaro Shimizu, Shun Okumura +2

Topological spin textures exhibit a hierarchical nature. For instance, magnetic skyrmions, which possess a particle-like nature, can aggregate to form superstructures such as skyrm…