  The antiferromagnetic domain wall dynamics is currently a hot topic in
mesoscopic magnetic systems. In this work, it is found that, based on the
Thiele approach, the motion of an antiferromagnetic domain wall is described by
the Duffing equation. Numerical simulations demonstrate that the
antiferromagnetic domain wall can be used as a Duffing oscillator, and the
transition between the periodic and chaotic motion can be used to detect the
periodic signal in the presence of the white noise. Furthermore, we calculate
the bifurcation diagram and Lyapunov exponents to study the chaotic behavior of
an antiferromagnetic domain wall. The numerical simulations are in good
agreement with the analytical solutions. Our results may be useful for building
spintronic detection devices based on antiferromagnetic domain walls.
