Alladi Ramakrishnan Hall

Skyrmions in solids: Classical crystals and quantum liquids

Arun Paramekanti

University of Toronto

Skyrmions are tiny topological magnetic swirls which can arise in crystalline or liquid forms in solid state materials. We theoretically show that nonlinear mode-coupling in skyrmion crystals leads to highly tunable skyrmion crystals. Conduction electrons coupled to such crystals exhibit novel Zeeman-field induced “topological quantum oscillations”. More broadly, we show that skyrmion crystals can also arise as a result of strain or frustrated magnetic interactions, and discuss its optical signatures via the Kerr effect. Finally, we show using numerical studies of model Hamiltonians in various 2D lattices as to how incorporating strong quantum fluctuations melts skyrmion crystals, leading to chiral quantum spin liquids with many-body topological order.