Wang, PeiPeiWangKehrein, StefanStefanKehrein2018-11-072018-11-072016https://resolver.sub.uni-goettingen.de/purl?gro-2/40619Weidentify a new class of phase transitions when calculating the Hall conductance of two-band Chern insulators in the long-time limit after a global quench of the Hamiltonian. The Hall conductance is expressed as the integral of the Berry curvature in the diagonal ensemble. Even if the Chern number of the unitarily-evolving wave function is conserved, the Hall conductance as a function of the energy gap in the post-quench Hamiltonian displays a continuous but nonanalytic behavior, that is it has a logarithmically divergent derivative as the gap closes. The coefficient of this logarithmic function is the ratio of the change of the Chern number for the ground state of the post-quench Hamiltonian to the energy gap in the initial state. This nonanalytic behavior is universal in two-band Chern insulators.CC BY 3.0journal_article10.1088/1367-2630/18/5/053003000377189800001https://resolver.sub.uni-goettingen.de/purl?gs-1/13380