Skyrmions

Magnetic skyrmions [1] are particle-like twists of the magnetization taking the form of nanoscale vortices or bubbles that are topologically protected from being continuously ‘unwound’. Their small size, high stability, and ease of manipulation by electric current make them strong candidates for use as information carriers in spintronic memory and logic devices. However, magnetic skyrmions have until recently been restricted to just a few materials and observed only at low temperatures, limiting the experimental accessibility and technological application of these unique...

The recently discovered Dzyaloshinskii-Moriya Interaction (DMI) in thin films has spawned a new direction for magnetism in spintronic application. This phenomenon stabilizes topological magnetic features including skyrmions and chiral domain walls (DWs) that can be manipulated by electric current with unprecedented efficiency. In this talk, I will review consequences of DMI on the structure of “Dzyaloshinskii” DWs and introduce the creep scaling law, which is paramount to describing a range of elastic interfaces including also superconductor flux lines and fluids being...

The field of spintronics, or magnetic electronics, is maturing and giving rise to new subfields. An important ingredient to the vitality of magnetism research in general is the large complexity due to competitions between interactions crossing many length scales and the interplay of magnetic degrees of freedom with charge (electric currents), phonon (heat), and photons (light). One perfect example, of the surprising new concepts being generated in magnetism research is the recent discovery of magnetic skyrmions. Magnetic skyrmions are topologically distinct...

Common magnets, such as refrigerator magnets and recorded bits in your hard disk, have aligned magnetic moments as compelled by the exchange interaction that causes ferromagnetism in the first place. Helimagnets are new types of magnets that exist in materials with broken inversion (non-centrasymmetric) symmetry, which enables the Dzyaloshinskii-Moriya interaction (DMI) to favor moments to be perpendicular to each other.  As a result of the competition, the ground state of a helimagnet is a spin helix and equally fascinating, the existence of skyrmion in...