  Nonlinear Hall effect (NHE) can originate from the quantum metric mechanism
in antiferromagnetic topological materials with PT symmetry, which has been
experimentally observed in MnBi2Te4. In this work, we propose that breaking PT
symmetry via external electric fields can lead to a dramatic enhancement of
NHE, thus allowing for an electric control of NHE. Microscopically, this is
because breaking PT symmetry can lift spin degeneracy of a Kramers' pair,
giving rise to additional contributions within one Kramers' pair of bands. We
demonstrate this enhancement through a model Hamiltonian that describes an
antiferromagnetic topological insulator sandwich structure.
