Fig. 1: Chiral dynamics with three evolution trajectories.
From: Chiral transmission by an open evolution trajectory in a non-Hermitian system
a, b Closed trajectory in a PT-symmetric system, with evolution trajectory encircling EPs (blue circle) and EP-excluding evolution trajectory (green circle). c, d Closed trajectory in an anti-PT-symmetric system. e, f Open trajectory without winding around EPs, and asymmetric mode conversion of asymptotic modes. Two EPs lie at (- ∞, + ∞) and (+ ∞, + ∞), and are not on the evolution trajectory. The circles in (a, c and e) represent the starting and ending points in the evolution trajectories. The purple and green arrows represent clockwise and counterclockwise directions in (b and d), respectively, and represent the forward and backward directions in (f), respectively
