antivortex

An antivortex is a topological defect characterized by a circulation or winding opposite to that of a reference vortex. In two-dimensional order-parameter fields, such as the phase of a superfluid or the orientation of spins in a magnet, a vortex surrounds its core with a certain sense of rotation, while an antivortex encircles with the opposite sense. Vortices and antivortices often appear as complementary defects and can annihilate each other to restore a uniform state.

In fluids and quantum fluids, antivortices are point-like or line-like defects where the local flow circulates in the reverse direction relative to a vortex. They can form bound vortex–antivortex pairs and interact through their velocity fields. Thermal fluctuations or external agitation can generate such pairs, and their collisions or annihilations release energy into the surrounding medium as waves or quasiparticle excitations.

In two-dimensional systems with a complex order parameter, the dynamics of vortices and antivortices are central to the Kosterlitz–Thouless transition. At low temperatures, vortices and antivortices exist predominantly in bound pairs, while at higher temperatures they unbind, leading to a change in the system’s correlation properties.

In superconductors and superfluids, antivortices carry opposite circulation or magnetic flux compared with vortices. They can influence magnetic and transport properties and, under suitable conditions, form lattice arrangements or annihilate with vortices.

In nanomagnetism and spintronics, antivortices describe spin textures with opposite curling of in-plane magnetization compared with vortices. These structures are studied for their stability and potential use in information storage and processing.

Overall, antivortices provide a counterpoint to vortices across fluids, quantum fluids, superconductors, and magnetic systems, reflecting the role of topological defects in nonlinear, low-dimensional physics.