# Gyrotropic elastic response of skyrmion crystals to current-induced tensions

## TL;DR

This paper develops an elasticity theory for skyrmion crystals in insulating chiral magnets, revealing how current-induced tensions and gyrotropic forces lead to steady motion and measurable transport effects.

## Contribution

It introduces a novel elasticity framework accounting for gyrotropic forces and boundary tensions, enabling prediction of transport phenomena in insulating skyrmion systems.

## Key findings

- Steady translation of skyrmion crystals can be induced by current tensions.
- The motion generates electromotive forces detectable as negative drag or positive magnetoresistance.
- Proposes non-local transport measurements to characterize chiral magnet phases.

## Abstract

We theoretically study the dynamics of skyrmion crystals in electrically-insulating chiral magnets subjected to current-induced spin torques by adjacent metallic layers. We develop an elasticity theory that accounts for the gyrotropic force engendered by the non-trivial topology of the spin texture, tensions at the boundaries due to the exchange of linear and spin angular momentum with the metallic reservoirs, and dissipation in the bulk of the film. A steady translation of the skyrmion crystal is triggered by the current-induced tensions and subsequently sustained by dissipative forces, generating an electromotive force on itinerant spins in the metals. This phenomenon should be revealed as a negative drag in an open two-terminal geometry, or equivalently, as a positive magnetoresistance when the terminals are connected in parallel. We propose non-local transport measurements with these salient features as a tool to characterize the phase diagram of insulating chiral magnets.