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Speaker: Chris Fechisin, UMD Title: Disclinations, dislocations, and emanant flux at Dirac criticality Abstract: What happens when fermions hop on a lattice with crystalline defects? The answer depends on topological quantum numbers which specify the action of lattice rotations and translations in the low energy theory. We find that disclinations and dislocations -- defects of crystalline symmetries -- generally lead in the continuum to a certain ``emanant'' quantized magnetic flux. To demonstrate these facts, we study in detail tight-binding models whose low-energy descriptions are (2+1)D Dirac cones. Our map from lattice to continuum defects explains the crystalline topological response to disclinations and dislocations, and motivates the fermion crystalline equivalence principle used in the classification of crystalline topological phases. When the gap closes, the presence of emanant flux leads to a non-zero current at zero applied magnetic flux. Journal Reference: https://arxiv.org/abs/2501.13866