Fig. 5: Demonstrating the existence of the hidden corner states of ML Nb3TeCl7.

a Schematic showing the state number of a \(L\)-size nanodisk with zero bulk polarization. b Counting the state number of the Nb3TeCl7 nanodisk of Configuration 2 \(\left( {L = 8} \right)\). There are 36 states between green arrows and 72 states between purple arrows. c Schematic showing the state number of a \(L\)-size nanodisk with nonzero bulk polarization. d Counting the state number of theNb3TeCl7 nanodisk of Configuration 1 \(\left( {L = 8} \right)\). There are 21 states between yellow arrows, 42 states between green arrows and 87 states between purple arrows.