  With respect to parity-time (PT) symmetry, anti-parity-time (APT) symmetric
system exhibits much easier readout mechanism due to its real frequency
splitting. Generally, such systems need to be operated at exceptional points
(EPs) to obtain the best performance. However, strict conditons to locate APT
symmetric systems at their EPs precisely put restraints on their practical
applications. To overcome this problem, we propose a scheme to manipulate the
EPs in APT symmetric configuration by Kerr effect. It is demonstrated that
operating EPs by self-phase modulation alone will impede the frequency
splitting caused by external perturbations, while cross-phase modulation can
enhance the response to measurable perturbations. We also investigate the
thermal effect induced by high light intensity, which could reduce the power to
manipulate EPs. This proposed scheme can pave a new way in fabricating devices
based on APT symmetry.
