Topological quantum phases cannot be characterized by Ginzburg–Landau type order parameters, and are instead described by non-local topological invariants. Experimental platforms capable of realizing ...

The Nature Index 2025 Research Leaders — previously known as Annual Tables — reveal the leading institutions and countries/territories in the natural and health sciences, according to their output in ...

Invariants should be well-formed formulas, that is, they should be logical statements (with a truth-value--true, of course), in the predicate calculus or rigorous English. A good invariant is a ...