The article deals with the use of the concept of topological equivalence, based on the adiabatic continuity principle of the Hamiltonians, when insulators are equivalent if they can be transformed into each other by a smooth transformation of one Hamiltonian into another without closing the gap
Ivchenko, E L.
"TOPOLOGICAL STATES IN RESONANT PHOTONIC CRYSTALS,"
Scientific-technical journal: Vol. 22
, Article 6.
Available at: https://uzjournals.edu.uz/ferpi/vol22/iss5/6