In this case it's about topological defects[1], also known as topological solitons, which is explained rather well on SE here[2].
Mathematicians and physicists try to give words to concepts, they don't always map well. As Wikipedia puts it:
Topological solitons arise with ease when creating the crystalline semiconductors used in modern electronics, and in that context their effects are almost always deleterious. For this reason such crystal transitions are called topological defects. However, this mostly solid-state terminology distracts from the rich and intriguing mathematical properties of such boundary regions. Thus for most non-solid-state contexts the more positive and mathematically rich phrase "topological soliton" is preferable.
Interesting. During my time in solid state physics and later quantum information, we just used "(topological) defects", not "topological solitons", though of course papers trying to sound cool could use that term. It takes about 2 uses to not conflate "defect" with anything deleterious, just the breaking of an otherwise functional symmetry.
Mathematicians and physicists try to give words to concepts, they don't always map well. As Wikipedia puts it:
Topological solitons arise with ease when creating the crystalline semiconductors used in modern electronics, and in that context their effects are almost always deleterious. For this reason such crystal transitions are called topological defects. However, this mostly solid-state terminology distracts from the rich and intriguing mathematical properties of such boundary regions. Thus for most non-solid-state contexts the more positive and mathematically rich phrase "topological soliton" is preferable.
[1]: https://en.wikipedia.org/wiki/Topological_defect
[2]: https://physics.stackexchange.com/questions/285731/what-is-a...