Z 2 topological signatures of the optical bound on maximal Berry curvature: Application to two-dimensional time-reversal symmetric insulators
The method uses measurable optical conductivity data to find a Z2 topological signature in two-dimensional time-reversal symmetric insulators. By deriving an 'optical bound' on maximal Berry curvature from refined trace-determinant inequalities, researchers can construct topological phase diagrams and identify symmetry-protected boundary states even when traditional Chern numbers are zero.