Longhi Stefano
Opt Lett. 2024 Mar 1;49(5):1373-1376. doi: 10.1364/OL.517182.
Anderson localization, i.e., the suppression of diffusion in lattices with a random or incommensurate disorder, is a fragile interference phenomenon that is spoiled out in the presence of dephasing effects or a fluctuating disorder. As a consequence, Anderson localization-delocalization phase transitions observed in Hermitian systems, such as in one-dimensional quasicrystals when the amplitude of the incommensurate potential is increased above a threshold, are washed out when dephasing effects are included. Here we consider localization-delocalization spectral phase transitions occurring in non-Hermitian (NH) quasicrystals with local incommensurate gain and loss and show that, contrary to the Hermitian case, the non-Hermitian phase transition is robust against dephasing effects. The results are illustrated by considering synthetic quasicrystals in photonic mesh lattices.
安德森局域化，即晶格中扩散在随机或非相称无序情况下的抑制，是一种脆弱的干涉现象，在存在退相效应或波动无序时会被破坏。因此，在厄米系统中观察到的安德森局域化 - 退局域化相变，比如在一维准晶体中，当非相称势的幅度增加到阈值以上时，在包含退相效应时就会消失。在这里，我们考虑在具有局部非相称增益和损耗的非厄米（NH）准晶体中发生的局域化 - 退局域化光谱相变，并表明，与厄米情况相反，非厄米相变对退相效应具有鲁棒性。通过考虑光子网格晶格中的合成准晶体来说明这些结果。
