Klaiman Shachar, Günther Uwe, Moiseyev Nimrod
Shulich Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Phys Rev Lett. 2008 Aug 22;101(8):080402. doi: 10.1103/PhysRevLett.101.080402. Epub 2008 Aug 21.
The visualization of an exceptional point in a PT-symmetric directional coupler (DC) is demonstrated. In such a system the exceptional point can be probed by varying only a single parameter. Using the Rayleigh-Schrödinger perturbation theory we prove that the spectrum of a PT-symmetric Hamiltonian is real as long as the radius of convergence has not been reached. We also show how one can use a PT-symmetric directional coupler to measure the radius of convergence for non-PT-symmetric structures. For such systems the physical meaning of the rather mathematical term radius of convergence is exemplified.
展示了在一个宇称-时间（PT）对称定向耦合器（DC）中异常点的可视化。在这样一个系统中，仅通过改变单个参数就可以探测到异常点。利用瑞利-薛定谔微扰理论，我们证明只要未达到收敛半径，PT对称哈密顿量的谱就是实的。我们还展示了如何使用PT对称定向耦合器来测量非PT对称结构的收敛半径。对于此类系统，举例说明了相当数学化的术语收敛半径的物理意义。
