Cooperative Charge Pumping and Enhanced Skyrmion Mobility

Area of Science:

• Condensed Matter Physics
• Spintronics
• Topological Matter

Background:

• Moving magnetic textures can induce spin and charge currents, known as electronic pumping.
• Ferromagnetic skyrmions are particle-like magnetic whirls with non-trivial topology.

Purpose of the Study:

• Investigate electronic pumping generated by steadily moving ferromagnetic skyrmions.
• Explore the role of magnetic topology in this phenomenon.
• Assess the scalability and potential applications of skyrmion-driven electronic pumping.

Main Methods:

• Solving the time evolution of the Schrödinger equation.
• Utilizing a tight-binding model and many-body statistical physics.
• Employing adiabatic scattering theory to compute pumped currents.

Main Results:

• Steadily moving skyrmions pump large direct currents, unlike rigid magnetic textures.
• The pumped current is linked to the skyrmion's nontrivial magnetic topology, combining spin-motive force and topological Hall effect.
• The pumped current scales with the reflection coefficient of conduction electrons off the skyrmion.

Conclusions:

• Skyrmion-driven electronic pumping is a scalable phenomenon, enhanced by reducing skyrmion and nanowire dimensions.
• This effect can be leveraged in racetrack memory devices to improve skyrmion collective motion.
• The interplay of topology and electronic transport offers new avenues in spintronic device design.