  Exceptional points (EPs), the degeneracy point of non-Hermitian systems, have
recently attracted great attention after its ability to greatly enhance the
sensitivity of micro-cavities is demonstrated experimentally. Unlike the usual
degeneracies in Hermitian systems, at EPs, both the eigenenergies and
eigenvectors coalesce. Although some of the exotic properties and potential
applications of EPs are explored, the range of EPs studied is largely limited
by the experimental capability. Some of the systems, e.g. with higher-order
EPs, are hard to achieve with conventional simulations. Here we propose an
extendable method to simulate non-Hermitian systems on the quantum circuits,
where a wide range of EPs can be studied. The system is inherently parity-time
(PT) broken due to the non-symmetric controlling effects and post-selection. A
sample circuit is implemented in a quantum programming framework, and the phase
transition at EP is demonstrated. Considering the scalable and flexible nature
of quantum circuits, our model is capable of simulating large scale systems
with higher-order EPs. We believe this work may lead to broader applications of
quantum computers and provide a tool to the studies for non-Hermitian systems
and the associated EPs.
