Hopfions, intriguing magnetic spin structures envisaged decades ago, have recently ignited fervent research interest. A collaborative effort between Swedish, German, and Chinese researchers, documented in Nature, presents the initial experimental proof.
Philipp Rybakov, a physicist at Uppsala University, Sweden, underscores the significance: “Our results bridge experimental physics and abstract mathematical theory, potentially paving the way for hopfions in spintronics.”
Understanding material components deeply is crucial for innovative materials and future tech. Spintronics, delving into electron spin, holds promise for melding electricity and magnetism.
Magnetic skyrmions and hopfions, topological structures, have captivated researchers for their particle-like properties, promising spintronic applications. Skyrmions are 2D vortex-like strings, while hopfions, 3D structures resembling twisted skyrmion strings, exhibit a donut-shaped form in the simplest case.
Although magnetic hopfions were synthetically observed previously, this study marks the first experimental evidence in B20-type FeGe crystal plates using transmission electron microscopy and holography, aligning with micromagnetic simulations.
The research introduces a unified skyrmion–hopfion homotopy classification, shedding light on diverse topological solitons in 3D chiral magnets. It opens avenues to explore stable hopfions in other crystals, study their interactions with electric and spin currents, delve into hopfion dynamics, and more.
Rybakov notes, “Hopfions, being novel, hold undiscovered properties, making predictions challenging. Yet, their potential in third-dimensional applications, enhancing technologies like racetrack memory, neuromorphic computing, and qubits, is intriguing due to an extra degree of freedom compared to skyrmions—moving in three dimensions rather than two.”
Source: Uppsala University