Microwave Tunneling and Robust Information Transfer Based on Parity-Time-Symmetric Absorber-Emitter Pairs
Pole diagram and impulse response. (a) Pole distribution of the transfer function on a Riemann surface. Grey solid line (prime meridian) marks the watershed between stable and unstable regions. The north pole is the pole in the case , corresponding to an open obstacle and leading to marginally stable operation. For the prototype, we fabricated ; there are eight poles in the transfer function, A, B, C, D, E, C, D, and E, where C, D, and E are the conjugates of C, D, and E, respectively. A and B are located on the 90-degree west longitude; C, D, and E are located close to the prime meridian but to the left; C, D, and E are located in the back surface. All these eight poles are in the stable region. (b) Numerical impulse response at the gain unit. The input port is excited with a pulse .