Ackerman Paul J, Boyle Timothy, Smalyukh Ivan I
Department of Physics, University of Colorado, Boulder, Colorado, 80309, USA.
Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado, 80309, USA.
Nat Commun. 2017 Sep 22;8(1):673. doi: 10.1038/s41467-017-00659-5.
Skyrmions are topologically protected continuous field configurations that cannot be smoothly transformed to a uniform state. They behave like particles and give origins to the field of skyrmionics that promises racetrack memory and other technological applications. Unraveling the non-equilibrium behavior of such topological solitons is a challenge. We realize skyrmions in a chiral liquid crystal and, using numerical modeling and polarized video microscopy, demonstrate electrically driven squirming motion. We reveal the intricate details of non-equilibrium topology-preserving textural changes driving this behavior. Direction of the skyrmion's motion is robustly controlled in a plane orthogonal to the applied field and can be reversed by varying frequency. Our findings may spur a paradigm of soliton dynamics in soft matter, with a rich interplay between topology, chirality, and orientational viscoelasticity.A skyrmion is a topological object originally introduced to model elementary particles and a baby skyrmion is its two-dimensional counterpart which can be realized as a defect in liquid crystals. Here the authors show that an electric field can drive uniform motion of baby skyrmions in liquid crystals.
斯格明子是拓扑保护的连续场构型，无法平滑地转变为均匀状态。它们的行为类似于粒子，并催生了有望用于赛道内存及其他技术应用的斯格明子学领域。揭示此类拓扑孤子的非平衡行为是一项挑战。我们在手性液晶中实现了斯格明子，并通过数值模拟和偏振视频显微镜，展示了电驱动的蠕动运动。我们揭示了驱动这种行为的非平衡拓扑保持纹理变化的复杂细节。斯格明子的运动方向在与外加场正交的平面中受到稳健控制，并且可以通过改变频率来反转。我们的发现可能会催生软物质中孤子动力学的范例，其中拓扑、手性和取向粘弹性之间存在丰富的相互作用。斯格明子是最初引入用于对基本粒子进行建模而提出的一种拓扑对象，而小斯格明子是其二维对应物，可作为液晶中的一种缺陷来实现。本文作者表明，电场可驱动液晶中小斯格明子的匀速运动。
