  Electrical magnetochiral anisotropy (EMCA) refers to the chirality- and
current-dependent nonlinear magnetoresistance in chiral conductors and is
commonly interpreted in a semimclassical picture. In this work, we reveal a
quantum geometry origin of EMCA by a chiral rectangular lattice model that
resembles a chiral organic conductor (DM-EDT-TTF)${}_2$ClO${}_4$ studied for
EMCA recently and exhibits symmetry-protected Dirac bands similar to those of
graphene. Compared to the semiclassical term, we find that Dirac states
contribute significantly to EMCA by the quantum metric when Fermi energy is
close to the Dirac point. Besides, we discovered topological insulator state
can emerge once SOC is added to our chiral model lattice. Our work paves a path
to understand quantum geometry in the magneto-transport of chiral materials.
