Many materials exhibit a multicomponent nature in their superconducting state. Notable examples include heavy-fermion compounds, Fe-based pnictides, and MgB₂. In these materials, superconductivity arises from electron condensates associated with different electron bands. Within the framework of Ginzburg-Landau theory, such phenomena can be described by multiple order parameters that are weakly coupled together.
A two-band superconductor in an external magnetic field can accommodate fractional vortices—whirls of supercurrent originating from different superfluid condensates. These vortices carry a fractional flux quantum and tend to attract each other, forming composite vortices with the full flux quantum Φ₀. However, due to differences in the vortex core sizes and condensate viscosities, composite vortices can dissociate into fractional components under the influence of a transport current.
In our research, we elaborate approaches to control the dissociation and recombination of composite vortices, manipulate their dynamics, and explore their applications in fluxonic devices.
Project Staff: Dr. Anton Pokusinkskyi
Major publications: