Liquid Crystals Offer On-Demand Skyrmions
Skyrmions are “twisty” arrangements of small, rod-shaped elements that might provide a stable, low-energy way to store information in the future. Researchers have now demonstrated the creation of skyrmions in a liquid crystal using any one of three inputs—laser light, an electric field, or heat [1]. Liquid-crystal skyrmions have been made before, but this new method uses a “pretwisting” process that lowers the energy barrier to forming these structures. The results could offer insights into creating skyrmions in magnetic materials.
In magnetic materials, skyrmions are compact, nanometer-sized patterns of spins. They are considered promising candidates for energy-efficient memory storage because they are resistant to environmental perturbations and can be moved around without consuming much energy. However, generating these skyrmions is challenging, requiring high-energy laser pulses or difficult-to-control heat inputs.
Chenhui Peng from the University of Science and Technology of China and colleagues study micrometer-sized skyrmions in liquid crystals, where the twisting elements are rod-shaped molecules rather than magnetic spins. “Our liquid-crystal skyrmions serve as an experimentally accessible analogue system [that] may inform future solid-state-device design,” Peng says.
The researchers placed their liquid crystal in a flat, 10-µm-thick box whose top surface was imprinted with a straight pattern and whose bottom surface was imprinted with a swirling pattern. These patterns exert an influence on the liquid-crystal molecules, causing them to form simple 2D twist arrangements. Next the researchers increased the amount of twisting by continuously rotating the top pattern over an angle of about 100° using a linearly polarized light beam. The effect was akin to rotating one end of a string while keeping the other end fixed. This pretwisting “primed” the liquid crystal for the transition to the more complex 3D twisted structure of a skyrmion.
To trigger this transition, the researchers used—in three separate experiments—laser light, an electric field, or heat. In each case, they observed skyrmion structures, which appeared as bright loops in microscope images. The fact that three different stimuli can generate skyrmions suggests that the mechanism is universal and that similar processes may be applied to other systems, Peng says.
–Michael Schirber
Michael Schirber is a Corresponding Editor for Physics Magazine based in Lyon, France.
References
- Q. Shi et al., “Multistimuli-controlled topological nucleation of skyrmion loops and monopoles in liquid crystals,” Phys. Rev. Lett. 136, 198101 (2026).