Taking a square root is not trivial. The Dirac equation is invented by the square root of the Kleind-Gordon equation. Then the lattice analog of the operation implies non-trivial topology and edge/corner states among the systems as the parent and children. We are proposing one more such example by the Cocktail glasses. Have a look at “Higher-Order Topological Insulator on a Martini Lattice and Its Square Root Descendant” by Daiki Matsumoto, Tomonari Mizoguch, and Yasuhiro Hatsugai, published in Phys. Soc. Jpn. 92, 034705 (2023). See also arXiv:2207.14540.